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Chapter 1
Introduction to Information and Communication
Learning Outcome
At the end of this chapter the students should be able to:
define and explain IT and ICT;
explain the concepts of ICT;
identify parts of the computer systems and their functions;
differentiate categories of computer peripherals; and
explain why computers are considered powerful thinking machines.
Learning Contents
Concepts of ICT and IT
Generations of Computers
-Types of Computers According to Size
The Computer System and its Parts and Categories
Uses of Computers In Modern Times
Information Technology (it)
 It is the use of computers to store, retrieve, transmit, and manipulate
data or information. IT is typically used within the context of business
operations as opposed to personal or entertainment technologies. IT is
considered to be a subset of information and communications
technology (ICT). An information technology system (IT system) is
generally an information system, a communications system or, more
specifically speaking, a computer system – including all hardware,
software and peripheral equipment – operated by a limited group of
Information and Communication Technology (ICT)
 It is an extensional term for information technology (IT) that stresses the
role of unified communications and the integration of
telecommunications (telephone lines and wireless signals) and
computers, as well as necessary enterprise software, middleware,
storage, and audiovisual systems, that enable users to access, store,
transmit, and manipulate information
 The term ICT is also used to refer to the convergence of audiovisual and
telephone networks with computer networks through a single cabling or
link system. There are large economic incentives to merge the
telephone network with the computer network system using a single
unified system of cabling, signal distribution, and management.
 ICT is an umbrella term that includes any communication device,
encompassing radio, television, cell phones, computer and network
hardware, satellite systems and so on, as well as the various services and
appliance with them such as video conferencing and distance learning.
 ICT is a broad subject and the concepts are evolving. It covers any
product that will store, retrieve, manipulate, transmit, or receive
information electronically in a digital form (e.g., personal computers,
digital television, email, or robots). Theoretical differences between
interpersonal-communication technologies and mass-communication
technologies have been identified by the philosopher Piyush Mathur.
Skills Framework for the Information Age is one of many models for
describing and managing competencies for ICT professionals for the
21st century.
Generations of Computers
Fifth Generation
What is Computer generation?
Computer Generation refers to the change in technology that is used for a
computer during a time period. Initially, the generation term was used to distinguish
between varying hardware technologies. But nowadays, generation includes both
hardware and software, which together make up an entire computer system.
First Generation (1940-1956)
Figure 2.13.
Vacuum tubes
Figure 2.14.
relay memory
 Punched cards
 Machine
language uses 0s
and 1s
 Stored program
Key Characteristics
 Bulky in size
 Highly unreliable
 Limited commercial
use and costly
 Difficult commercial
 Difficult to use
 Processing speed:
Example of
IBM 701
Second (1956-1963)
Figure 2.15.
 Assembly
 Batch operating
 High-level
 Programming
 Scientific and
 Faster, smaller, more
reliable and easier to
program than
previous generation
 Commercial
production was still
difficult and costly
 Processing speed:
Honeywell 400
IBM 7030
IBM 1401
CDC 1604
 Timesharing
operating system
 Standardization
of high-level
 Unbundling of
software from
 Faster, smaller, more
reliable, easier and
cheaper to produce
 Commercially, easier
to use, and easier to
upgrade than
previous generation
 Scientific,
commercial and
interactive on-line
 Processing speed:
IBM 360/370
CDC 6600
Figure 2.16.
Magnetic cores
 Magnetic tapes
Disks for secondary
Third (1964-1971)
Figure 2.16.
Integrated Circuits
 ICs with SSI and
MSI technologies
 Larger magnetic
cores memory
 Larger capacity
disks and
magnetic tapes
 Keyboard and
Fourth (1971-present)
Figure 2.17.
Microprocessors or
Large Scale IC
 Microprocessors;
 Larger capacity
hard disks as inbuilt secondary
 Magnetic tapes
and floppy disks
as portable
storage media
 Pointing devices
like mouse and
handled devices
 Personal
 Supercomputers
based on parallel
vector processing
and symmetric
Spread of highspeed computer
 Operating
systems for PCs
with GUI and
multiple windows
on a single
terminal screen
 Multiprocessing
OS with
 UNIX operating
system with C
 Object-oriented
design and
 PC, Networkbased, and
 Small, affordable,
reliable, and easy to
use PCs
 More powerful and
reliable mainframe
systems and
 Totally general
purpose machines
 Easier to produce
 Easier to upgrade
 Rapid software
 Processing speed:
 IBM PC and its
 Apple II
 TRS-80
 VAX 9000
 CRAY-1
 CRAY-2
Fifth (present- beyond)
Figure 2.18. Artificial Intelligent
 Super Large Scale Integrated (SLSI)
chips that are able to store millions of
components on a single chip Larger
ULSI technology
Development of true artificial
Development of Natural language
Advancement in Parallel processing
Advancement in Superconductor
More user friendly interfaces with
multimedia features
capacity main memory, hard disks with
RAID support
Optical disks as portable read-only
storage media
Very large memory
Notebooks, powerful desktop PCs and
Powerful severs, supercomputers
Cluster computing
Availability of very powerful and
compact computers at cheaper
Classification of Computers
A. According to Purpose
1. General-purpose digital computer. This is also called all-purpose digital
computer. It can be used for any type of application.
Ex.: Computers that are used for payroll, graphics, analysis, etc.
2. Special purpose digital computer. These computers designed to solve
problems of a restricted type i.e. designed to be especially efficient in a
certain class of applications.
Ex.: Embedded systems like ATM machines.
B. According to Data Handled
1. Analog Computers. Computers that are in which
numerical magnitudes are represented by physical quantities,
such as electric current, voltage or resistance, mechanical
movements, pressure or temperature. Analog computers
accept data and then process it to produce analog data.
Figure 2.19. Example of Analog
Computer (Donner 3000)
2. Digital Computers. Work with values that are in a discrete form (or data that
can be counted). They are used for business applications,
and also scientific operations, and are ideal when 100%
accuracy is desired, thus resulting to data that are exact in
Figure 2.20. Digital Computer
3. Hybrid Computers. This computer is the outcome of the integration of analog
computer components and digital components. This
integration is obtained by digital –to-analog converter and
analog –to-digital converter. These computers are usually used
in space vehicle simulation and training astronauts.
Figure 2.21. Example of Hybrid Computer (DPD 45)
4. According to Capacity
Capacity refers to :
 amount of data that can be stored in memory;
 speed of internal operation of the other computer;
 capacity of storage devices; and
 number and types of peripheral devices.
a. Microcomputers
Figure 2.22. Desktop Computer
Small computers which are portable. Uses
microprocessor (the CPU on a chip), Read-Only
Memory (ROM) and a Random Access Memory
(RAM). It is sometimes known as a Single-Chip
Processor.Examples: Desktop and floor standing
units, Luggable,Laptops,Notebooks, Pocket PC’s
and Pen Computers.
b. Minicomputers
These are machines that are in the middle of
microcomputers and mainframes in terms of cost
and capability. Medium-capacity computer that is
larger than a microcomputer but smaller than most
mainframes. A minicomputer can handle a larger
amount of data than a microcomputer and can
Figure 2.23. Minicomputers
perform most of the functions of a mainframe.
These acts as ‘servers’, which are connected to
several workstations or terminals.
c. Mainframes.
Figure 2.24. IBM 370
The oldest category, air-cooled ,bigger in
sizes, about the size of a jeep and a powerful
computer, often serving many connected terminals
and usually used by large complex organizations
like banks, airlines and insurance companies that
handles millions of transactions.
d. Supercomputers
The biggest and fastest computers. They can
perform 50 million instructions per second and are
used in applications such as nuclear weapon
development and accurate weather forecasting.
These are the fastest calculating device ever
Figure 2.25. IBM DEEP
 It is a collection of entities (hardware, software and humanware) that
are designed to receive, process, manage and present information in a
meaningful format.
Figure 3.1. A computer system operates on three significant components.
 It consists primarily of four basic units: the input unit, the storage units, the
central processing unit and the output unit. A computer performs five
major operations or functions regardless of its size and make.
These are:
It accepts data or instructions as input;
It stores data and instruction;
It processes data as per the instructions;
It controls all operations inside a computer, and ;
Its gives results in the form of output.
Logic Unit
Control Unit
Indicates flow of instructions and data
Indicates the control exercised by the
control unit
Figure 3.1. Computer System basic Operation
Input Unit. It used for transfers’ raw data and control signals into
the information processing system by the user before processing and computation.
All the input unit devices provide the instructions and data are transformed into binary
codes that is the primary memory acceptable format.
The functions of the input unit are:
accept data and set of instructions/command;
convert the data in a form which the computer can accept;
provide this converted data to the computer for further
Central Processing Unit. This is called the brain of the computer system. It
consists of three parts namely, the control unit; the arithmetic logic unit; and the
primary storage unit.
a. Control Unit
- It controls, manages and coordinates the operations of the
entire computer system.
b. Arithmetic Logic Unit
- It executes the instructions and performs all the calculations
and decisions.
c. Primary Storage Unit
- It is also called as main memory
- the data which is to be output from the computer system is
also temporarily stored
- it is the storage section that holds the computer programs
during execution
- it Stores temporary results of intermediate processing
Output Unit. It give the results of the process and computations to the outside
world. The output units accept the results produced by the computer, convert them
into a human readable form and supply them to the users.
Computer hardware – It consists of internal and peripheral devices. All physical
parts of the computer or everything that we can touch.
e.g.:Input devices, output devices, central processing unit and
storage devices
Computer software - also known as programs or applications. It gives
“intelligence” to the computer. They are classified into two
classes namely - system software and application software
Humanware – it is the person who operates computer. The user commands
the computer system to execute on instructions.
Computer Hardware Components
Hardware. It consists of all the machinery and equipment in a computer system.
In general, computer hardware is categorized according to which of the five
computer operations it performs.
Input devices
Processing devices
Storage devices
Output devices
Input Devices. It is any electronic devices connected to a computer that produce
input signals. It is also used to enter the data and instructions into the computer.
It translate data from form that humans understand to one that the
computer can work with.
Classification of Input Devices
a. Input Devices for Texts and Images
It is the primary input device
that is used to enter data into
a computer or any other
electronic device by pressing
keys. It uses USB or a Bluetooth
communication to connect to
a computer.
Flatbed Scanner
Handheld Scanner
It used to capture a source document and
converts it into an electronic form.
Barcode Reader
Graphics Table
It is also known as
barcode scanner or point
of sale (POS) scanner, is
an input device capable
of reading barcodes.
Optical Mark Reader
It is an electronically
extracting intended data
from marked fields, such
as checkboxes and fillinfields, on printed forms.
OMR technology scans a
printed form and reads
predefined positions and
records where marks are
made on the form.
Digital Camera
Magnetic Ink Character Reader
It used by artists which allow
them to draw a picture onto a
computer screen without
having to use a mouse or
keyboard. It consists of a flat,
touch-sensitive pad and a
drawing device, either a pen
or stylus.
a device used for
machine recognition of
numeric data printed with
magnetically charged ink. It
is used on bank checks and
A device that takes
photographs and stores
the image as data on
a memory card.
Figure 3.3. List of Input devices for Texts and Images
b. Input Devices for Audio
Is an input device that allows users to input audio into their computers. Here are
some uses of the microphone:
- Audio for video
- Computer gaming
- Online chatting
- Recording musical instruments -Recording voice for dictation, singing and podcasts
- Voice recorder
- Voice recognition - VoIP – Voice over Internet Protocol
MIDI Keyboard
It is a controller keyboard, like a typically a piano-style electronic musical
keyboard, often with other buttons, wheels and sliders, used for sending MIDI
signals or commands over a USB or MIDI 5-pin cable to other musical devices or
Figure 3.4. List of Input devices for Audio
c. Input Devices for Video
CCTV Camera
Digital Video Camera
Video input are motion images captured into
the computer by special input devices.
Figure 3.4. List of Input devices for Video
d. Pointing Device
Pointing Device is an input device that allows a user to control a pointer on a screen. A
pointer is a small symbol on the screen whose location and shape change as a user
moves a pointing device
Figure 3.5. List of Pointing Input devices
Output Devices. Hardware that is capable of delivering or showing information to
one or more users. An output device displays, prints and presents the results of a
computers work.
After processing the inputted data, the computer will give its output. This output
can be in two different formats:
1. Softcopy – Visual (monitor) or Sound (speakers)
2. Hardcopy – Output on a tangible (something you can touch) such as a
printer printout
Different Types of Output Devices
LCD Monitor
LCD Monitor
LED Monitor
LCD Projector
Dot Matrix Printer
Laser Printer
Ink Jet Printer
Thermal Printer
Figure 3.7. Different Types of Output Devices
Storage Devices. It is any hardware device that is used for storing, porting and
extracting data files and objects. It can hold and store information either temporarily
and permanently, and can be internal or external to a computer.
Types of Computer Storage
1. Primary storage
2. Secondary storage
1. Primary Storage. Primary storage is the main memory in a computer. It stores
data and programs that can be accessed directly by the processor.
There are two types of primary storage which are RAM and ROM
Figure 3.8. RAM and ROM
Table 3.1. The Difference between RAM and ROM
Random-Access Memory (RAM)
Read-Only Memory (ROM)
RAM is an acronym for Random- Access ROM is an acronym for Read- Only
Memory which means the data and Memory. The data or program in ROM can
program in RAM can be read and only be read but cannot be written at all
RAM stores data during and after ROM is another type of memory
processing. RAM is also known as a permanently stored inside the computer.
working memory.
The data in RAM can be read (retrieved) All the contents in ROM can be accessed
or written (stored).
and read but cannot be changed.
RAM is volatile which means the ROM is non-volatile. It holds the programs
programs and data in RAM are lost and data when the computer is powered
when the computer is powered off.
A computer uses RAM to hold temporary
instructions and data needed to
complete tasks. This enables the CPU
(Central Processing Unit) to access
instructions and data stored in the
memory very quickly
It can only be stored by the manufacturer
once and it cannot be changed.
2. Secondary Storage - Secondary storage is another alternative storage to save
your work and documents. This can be removable, internal, or external. It is very
useful to store programs and data for future use. It is non-volatile, which means
that it does not need power to maintain the information stored in it. It will store
the information until it is erased.
Figure 3.9. Types of Secondary Story
Types of Secondary Storage
a. Magnetic Medium. It is a non-volatile storage medium. It can be any type of
storage medium that utilizes magnetic patterns to represent information.
Examples of magnetic storage are magnetic disk such as a floppy disk, used
for off-line storage; hard disk, used for secondary storage and magnetic tape
such as video cassette; audio storage reel-to-reel tape.
Floppy Disk
Magnetic Tape
Hard Disk
Video Cassette
Figure 3.10. Types of Magnetic Medium
b. Optical Medium. It is a non-volatile storage media, holds content in digital form
that are written and read by laser. These media include various types of CDs
and DVDs.
Types of Optical Medium
Figure 3.11. Types of Optical Medium
c. Flash Memory. It is a solid-state, non-volatile, rewritable memory that functions
like RAM and a hard disk drive. Flash memory store bits of electronic data in
memory cells just like DRAM (Dynamic RAM) but it also works like a hard disk
drive that when the power is turned off, the data remains in the memory. Flash
memory cards and flash memory sticks are examples of flash memory.
Types of Flash Memory
Solid State Hard
Memory Stick
Flash memory
Micro Flash Memory
Figure 3. 12. Types of Flash Memory
CAPACITY. It refers to the number of bytes (characters) a storage medium can hold
1 Byte = 8 Bits
1 KB = 1024 Byte
1 Megabyte = 1024 Kilobyte
1GB = 1024 MB
1 Terabyte (TB) = 1 trillion byte
1 Petabyte (PB) = 1 quadrillion byte
1 Exabyte (EB) = 1 quintillion byte
1 Zetabyte (ZB) = 1 sextillion byte
1 Yotabyte (YB) = 1 septillion byte
Table 3.2. Different Storage Capacity
System Unit
The system unit is a boxlike case that houses the computer’s main hardware
Parts of a System Unit
Motherboard/Mainboard. The motherboard is the
main circuit board holding the integrated circuits for the
microprocessor, memory, etc. The motherboard also
supports internal connectors for the hard disk drives &
optical drives (CD, DVD), etc, and external connectors
for the mouse, keyboard, printer, speakers, etc.
Figure 3.13. Motherboard
Figure 3.14. Hard Disk Drive
2. Hard Disk Drive Storage (HDD). It used as the main
storage device for programs and data when the computer is
not being used. Information is stored on the hard drive
magnetically and the capacity of the device is usually
measured in Megabytes, Gigabytes, or Terabytes, etc.
3. Optical Drive (CD/DVD). A DVD drive allows removable
optical discs to be used to store information.
Figure 3.15. Optical Drive
Figure 3.16. Memory
4. Memory/RAM. Memory is the processor’s working area
and is here all operations actually take place while the
computer is running.
Memory is also called Random Access Memory and
consists of small memory ‘chips’ which fit into slots on the
5. Microprocessor/Central Processing Unit/CPU. This is
the ‘computer on a chip’ and is the device which
actually executes the instructions.
Figure 3.17. Microprocessor/CPU
Components of the CPU
a. Control unit. Coordinates and controls all parts of the computer
b. Arithmetic-logic unit. Performs arithmetic or
logical operations
c. Registers. Temporarily store the most frequently used instructions
Figure 3.18. Processor
and data
6. Computer Power Supply. This supplies the electricity to all
the parts in the computer.
Figure 3.19. Computer Power Supply
7. Heat Sink/Fan. This sits on top of the CPU and draws heat
up into the fins of the Heat Sink, and then the Fan pulls air up
and through the fins cooling them. That is how the CPU is stays
cool, otherwise it would over heat and shut down the
Figure 3.20. Heat Sink/Fan
8. Network card. Attach to the PCI (Peripheral component
interconnect ) slot used for a Broadband connection, like
cable or DSL.
Figure 3.21. Network Card
9. Sound Card. It is a computer expansion card that
facilitates the input and output of audio signals to and from a
computer under control of computer programs.
Figure 3.22. Sound Card
10. Graphics Card. It is an expansion card whose function
is to generate and output images to a display
Figure 3.23. Graphics Card
11. Chipset. It is a collection of chips that provide the
switching circuitry needed to move data throughout the
Figure 3.24. Chipset
12. Cooling Fan. Cooling Fan is used for cooling purposes.
Figure 3.25. Cooling Fan
13. CMOS Battery. It provides CMOS with the power when
the computer is turned off all motherboards comes with a
battery. These batteries mount on the motherboard in one
of three ways: the obsolete external battery, the most
Figure 3.26. CMOS Battery common onboard battery, and built-in battery.
CMOS – Complementary Metal Oxide Semi- Conductor
14. IDE (Integrated Drive Electronics) Controller. It is
responsible for controlling the hard drive and CDROM.
Figure 3.27. IDE (Integrated Drive Electronics) Controller
15. SATA (Serial Advance Technology Attachment)
Controller. Major upgrade of IDE controller, responsible for
controlling the hard drive and CDROM.
Figure 3.28. SATA (Serial Advance Technology Attachment)
Computer Software Components
Computer Software
It refers to the set of computer programs, procedures that describe the
programs, how they are to be used. We can say that it is the collection of programs,
which increase the capabilities of the hardware. Software guides the computer at
every step where to start and stop during a particular job. The process of software
development is called programming.
Computer software is a generic term for organized collections of code
representing instructions executed by a computer. Software is often written first as
source code, and then converted to a binary format that is specific to the device on
which the code will be executed.
Categories of Software
Computer software is normally classified into two broad categories.
System Software
Application Software
 It is responsible for controlling, integrating, and managing the individual
hardware components of a computer system so that the other software
and the users of the system see it as a functional unit without having to
be concerned with the low-level details such as transferring data from
memory to disk, or rendering text onto a display.
 These are general programs designed for performing tasks such as
controlling all operations required to move data into and out of the
 It communicates with printers, card reader, disk, tapes etc. monitor the
use of various hardware like memory, CPU etc.
So without system software it is impossible to operate your computer. The
following diagram is shown in Figure 3.29 is the relation between hardware, software
and you as a user of computer system.
Figure 3. 29. Relation between hardware, software and user
Types of System Software
1. Operating System
 It is software that controls and monitors the running of applications
 It provides a “platform” for software developers who have to
design applications with the OS in mind.
 It is responsible for the management and coordination of
activities and the sharing of the resources of the computer
 It is an interface between computer and user.
Figure 3.30. Operating System is an interface between computer
and user
Function of an Operating System
The part of the OS that manages the computer’s resources is known as
the Kernel (otherwise known as the supervisor program). It manages the
computer’s resources (CPU, memory and peripherals).
Allocation and
Backing Store
I/O System
Figure 3.31. Function of an Operating System@ guru99.com
Most operating systems perform the following tasks:
a. Memory Management. In several programs can be opened at once,
the OS has to allocate memory to each program that is running,
including itself.
b. Resource Allocation and Sharing. Some computer systems can
“multi-task”, i.e. several programs can run at once. The OS allocates
processing time, memory and resources to each.
c. Backing Store Management. The OS maintains a directory of the HDD
so that files and free space can be located quickly. The OS controls
the transfer of the data from disk to memory and back again.
d. Interrupt Handling. The OS will detect “interrupts”, e.g. when the
printer is out of paper; when the user is pressing the ESC key; or when
a hardware device or an application is malfunctioning. The OS will
display the appropriate error message and may suggest corrective
action to the user.
e. Process management. It helps OS to create and delete processes. It
also provides mechanisms for synchronization and communication
among processes.
f. File management. It manages all the file-related activities such as
organization storage, retrieval, naming, sharing, and protection of
g. Device Management. It keeps tracks of all devices. This module also
responsible for this task is known as the I/O controller. It also performs
the task of allocation and de-allocation of the devices.
h. I/O System Management. One of the main objects of any OS is to
hide the peculiarities of that hardware devices from the user.
i. Secondary-Storage Management. Systems have several levels of
storage which includes primary storage, secondary storage, and
cache storage. Instructions and data must be stored in primary
storage or cache so that a running program can reference it.
j. Security. This module protects the data and information of a
computer system against malware threat and authorized access.
k. Command interpretation. This module is interpreting commands
given by the acting system resources to process that commands.
l. Networking. A distributed system is a group of processors which do
not share memory, hardware devices, or a clock. The processors
communicate with one another through the network.
m. Job accounting. It keeps track of time & resource used by various job
and users.
n. Communication management. The Coordination and assignment of
compilers, interpreters, and another software resource of the various
users of the computer systems.
Types of Operating System
Sharing OP
Real Time
Figure 3.32. Types of Operating System
1. Batch Operating System
Figure 3.33. Batch Operating System
Some computer processes are very lengthy and time-consuming.
To speed the same process, a job with a similar type of needs are
batched together and run as a group.
The user of a batch operating system never directly interacts with
the computer. In this type of OS, every user prepares his or her job
on an offline device like a punch card and submit it to the
computer operator.
2. Multi-Tasking/Time-sharing Operating Systems
Figure 3.34. Multi-Tasking/Time-Sharing Operating System
Time-sharing operating system enables people located at a
different terminal (shell) to use a single computer system at the
same time.
The processor time (CPU) which is shared among multiple users is
termed as time sharing.
3. Real time
Application Program
Real Time Operating System
Figure 3.35. Real Time Operating System
 It is also known as embedded operating system and it is totally
depending upon the clock interrupts.
 A real time operating system time interval to process and respond to
inputs is very small. Examples: Military Software Systems, Space
Software Systems.
4. Distributed Operating System
File Server
Database Server
Computer Node
Figure 3.36. Distributed Operating System
 It is used in many processors located in different machines to provide
very fast computation to its users.
 It is a model where distributed applications are running on multiple
computers linked by communication network.
 It is also an extension of the network operating system that supports
higher levels of communication and integration of the machines on
the network.
5. Network Operating System
Network Operating System runs on a server. It provides the capability to serve
to manage data, user, groups, security, application, and other networking
File Server
Figure 3.37. Network Operating System
Mobile OS
Figure 3.38. Mobile Operating System
Is are those OS which is especially that are designed to allows and power
smartphones, tablets, and wearables devices to run applications and
Some most famous mobile operating systems are Android and iOS, but
others include BlackBerry, Web, and watchOS.
Examples of Operating System
The Unix Operating System. It was first created in Bell Labs way
back in the 1960s. It became popular in the 1970s for high-level
computing, but not on the consumer level. Since a lot of Internet
services were originally hosted on Unix machines, the platform
gained tremendous popularity in the 1990s. It still leads the
industry as the most common operating system for Web servers.
The Macintosh OS (Mac OS). Develop by Apple Computer in
January 24, 1984. It is pre-installed on the Macintosh 128K model
computer. The Mac OS is credited for the widely used feature of
every OS to date. The GUI (Graphical User Interface); the use of
icons, buttons a pointing cursor, and a point and click command
to execute instructions rather than the usual command line driven
commercialized by Microsoft. It was the most dominant
operating system for the PC compatible platform during the
1980’s. It is command line driven interface program where the
user interacts with the computer through command prompts to
execute different program.
Microsoft Windows Operating System. It is first introduced an
operating environment named Windows in November 1985 as an
add-on to MS-DOS in response to the growing interest in graphical
user interface (GUI).
Linux Operating System. Linux is an open source operating
system (OS) for personal computers, servers and many other
hardware platforms that is based on the Unix operating system.
Linux was originally created by Linus Torvalds as a free alternative
operating system to more expensive Unix systems. Linux has
grown since its creation due in part to its open source roots. Open
source software is freely licensed and users may copy and even
change the code.
There are several operating systems that use the Linux
kernel. These include: Ubuntu, Debian, Red Hat, Fedora, Chrome
OS and Android (for smartphones).
2. Utilities Programs
 This are small, powerful programs with a limited capability, they
are usually operated by the user to maintain a smooth running of
the computer system. Various examples include file
management, diagnosing problems and finding out information
about the computer etc. Notable examples of utility programs
include copy, paste, delete, and file searching, disk
defragmenter, disk cleanup.
3. Device Drivers
 Specialized programs that allow communication between a
device and the computer. Loaded into memory each time a
computer is started. When a new device is added, new device
drivers must be installed.
It is a type of software that performs task to directly
benefit or assist the user. It is installed on top of an Operating
System such as MS Windows.
Types of application software
a. Proprietary Application Software / Customized Software. It is software
designed for a particular customer. In this case we need to hire a
computer programmer or software creator to develop software for the
b. Packaged software. It is the kind of “off-the-shelf application software”
program developed for sale to the general public. It can be purchased
programs, leased, or rented from a vendor that develops programs and
sells them to many organization. The word package is a commonly used
term for a computer program (or group of programs) that has been
developed by a vendor and is available for purchase in a prepackaged
Examples of Application Software
1. Word Processing software - Use this kind of tool to create worksheets,
type letters, and type papers. The following examples are MS Word,
WordPerfect, MS Works, and AppleWorks.
2. Desktop Publishing software - Use this software to make signs,
banners, greeting cards, illustrative worksheets, newsletters, etc. The
following examples are Adobe PageMaker, MS Word, MS Publisher,
AppleWorks, MS Works, and Quark Express.
3. Spreadsheet software - Use this kind of tool to compute numberintensive problems such as budgeting, forecasting, etc. A
spreadsheet will plot nice graphs very easily. The following examples
are MS Excel, Quattro Pro, Lotus 1-2-3, MS Works, and AppleWorks.
4. Database software - Use this software to store data such as address,
membership and other text information. A database can be used to
easily sort and organize records. The following examples are MS
Access, Filemaker Pro, AppleWorks, and MS Works.
5. Presentation software - Use this software to create multimedia stacks
of cards/screens that can effectively present a lesson or a sales pitch.
The user often clicks on buttons to advance to the next screen in a
sequence. The following examples are MS PowerPoint, AppleWorks
(slideshows), HyperStudio, Flash, Director, HyperCard, Digital Chisel,
SuperCard, and Corel Envoy.
6. Internet Browsers - This software allows one to surf the Web. Often they
can read email and create Web pages too. The following examples
are Netscape Navigator (or Netscape Communicator), MS Internet
Explorer, AOL Browser, Google Chrome, Mozilla Firefox, Opera Web
Browser, and Safari Web Browser.
7. Email programs - These programs send and receive email. The
following examples are Netscape Messenger (part of Netscape
Communicator), MS Outlook Express, MS Outlook, Eudora, and AOL
8. Graphics Programs (pixel-based) - This software allows one to touch
up photographs and create graphics from scratch. The following
examples are Adobe Photoshop, Paint Shop Pro, AppleWorks, MS
Works, MS Paint (comes free on Windows PC's), and Painter.
9. Graphics Programs (vector-based) - This software creates graphics
that are similar to illustrations or cartoon drawings. The following
examples are Adobe Illustrator, Corel Draw, AppleWorks, MS Works,
and MS Word.
10. Communications software - This software allows two computers with
modems to communicate through audio, video, and/or chat-based
means. The following examples are MS NetMeeting, AOL Instant
Messenger, IRC, ICQ, and CU-SeeMe.
Capabilities of Software
a. Object Linking and Embedding (OLE). It allows information to be shared
between applications, e.g. a spreadsheet created in Excel can be
imported into Word.
b. Portability of Data. People, who have different types of computers with
different operating systems and applications, often need to transfer files
and programs among their computers. FTP (File Transfer Protocol) allows
files to be transferred over the Internet among different types of
c. Upgradability. Software upgrades can provide new and useful features
but they can also cause problems, such as documents may not be
compatible versions, e.g. a Word 6 file can be read in Word 97 but a
Word 97 file cannot be read in Word 6; data formatting may be lost if a
Word 97 document is saved to Word 6 format because Word 97 contains
new features that Word 6 does not have; upgraded software frequently
required more memory, more disk space and a faster processor, so
hardware need to be upgraded.
It describes the customer experience of software and hardware. More
particularly, it has to do with the facilities of a computer system being
developed based on the interests and needs of a user.
It is also called as the living ware. It refers to the users of the computer
system, either direct or indirect users.
Individual people who
uses computer in their
job, entertainment etc.
Web Developer
Figure 3.39. Different types of humanware
Computer Engineers.
o they are engage in software design and application to address
the needs of a particular industry or sector. They are primarily
responsible for the update in the software as well as providing
additional customization of current software to ensure the
system’s functionality.
Software Engineers
o they are primarily responsible for the design and development of
the software of the computers, as well as its testing and
Information Technology Specialists
o they tasked to plan and coordinate the installation, operation,
troubleshooting and maintenance of the computer’s software
and hardware systems.
Website Designer
o they are engage in the construction of the navigation schemes of
a website.
Compute Technicians
o They in charge with the repair and maintenance of computers
and its servers
o They also build or configure new hardware as well as installing and
bringing up to date the software
o They are also tasked with the creation and maintenance of
computer networks.
Computer Operator
o They are responsible for monitoring and controlling computer
systems especially mainframe computer systems in a company or
System Analyst
o They work to solve problems related to computer technology.
Many analysts set up new computer systems, both the hardware
and software; add new software applications to increase
computer productivity.
Project Manager
o They are the person who has the overall responsibility for the
successful initiation, planning, design, execution, monitoring,
controlling and closure of a project.
o They refer to a specialist in one area of computer programming or
to a generalist who writes code for many kinds of software.
Database Administrator
o They are responsible for the performance monitoring, security,
integrity, troubleshooting, as well as backup and data recovery of
a database. They use specialized software to store and organize
Server Administrator
o It has the overall of a server. This is usually in the context of a
business organization, where a server administrator overseas the
performance and condition of multiple servers in the business, or it
can be in the context of a single person running a game server.
1. Information Systems/Data Processing
Information System or Data Processing refers to a category of computer use that
enables organization to utilize to the fullest the data they possess.
2. Personal Computing
Small and medium-size businesses as well as individuals form the bulk of personal
computing practitioners. Personal computing means the use of stand-alone
computers equipped with all the system, utility, and application software and I/O
devices that an individual needs to perform one or more tasks.
3. Science and Research
Result of scientific endeavors would take a long time to realize if it were not for the use
of computers in this specialty area.
4. Education
Although computers will never replace books and teachers, the can enhance
learning in a way no other medium can. Through its interactive capability, computers
have added a new dimension to the learning process.
5. Artificial Intelligence
Artificial intelligence is an area of computer research which aims to endow the
computer with certain forms of human intelligence such as the capability to
understand natural language or to reasons under uncertain condition.
Field of Artificial Intelligence is divided into four categories:
1. Knowledge-based and expert system refers to man’s knowledge based on his
judgment algorithmic sense about a specific application area.
2. Natural languages refer to software that enables computer systems to accept,
interpret and execute instructions written in the native or natural language or
the end user.
3. Simulation of human sensory capabilities in computer system, such as seeing,
hearing and touching, has been made possible, although in varying report,”
the computer will obligingly follow.
4. Robotics refers to the use of computerized robots in the manufacturing sector.
Industrial robots, which are usually equipped with an arm and a hand, can be
instructed to do repetitive tasks such as screwing on the bolts or painting cars.
The Computer System and its Parts and Categories
What is a Computer System?
A computer is a machine that can be instructed to carry out sequences of
arithmetic or logical operations automatically via computer programming. Modern
computers have the ability to follow generalized sets of operations, called programs.
These programs enable computers to perform an extremely wide range of tasks. A
"complete" computer including the hardware, the operating system (main software),
and peripheral equipment required and used for "full" operation can be referred to as
a computer system. This term may as well be used for a group of computers that are
connected and work together, in particular a computer network or computer cluster.
Computers are used as control systems for a wide variety of industrial and
consumer devices. This includes simple special purpose devices like microwave ovens
and remote controls, factory devices such as industrial robots and computer-aided
design, and also general purpose devices like personal computers and mobile
devices such as smartphones. The Internet is run on computers and it connects
Early computers were only conceived as calculating devices. Since ancient
times, simple manual devices like the abacus aided people in doing calculations.
Early in the Industrial Revolution, some mechanical devices were built to automate
long tedious tasks, such as guiding patterns for looms. More sophisticated electrical
machines did specialized analog calculations in the early 20th century. The first digital
electronic calculating machines were developed during World War II. The first
semiconductor transistors in the late 1940s were followed by the silicon-based MOSFET
(MOS transistor) and monolithic integrated circuit (IC) chip technologies in the late
1950s, leading to the microprocessor and the microcomputer revolution in the 1970s.
The speed, power and versatility of computers have been increasing dramatically
ever since then, with MOS transistor counts increasing at a rapid pace (as predicted
by Moore's law), leading to the Digital Revolution during the late 20th to early 21st
Conventionally, a modern computer consists of at least one processing
element, typically a central processing unit (CPU) in the form of a metal-oxidesemiconductor (MOS) microprocessor, along with some type of computer memory,
typically MOS semiconductor memory chips. The processing element carries out
arithmetic and logical operations, and a sequencing and control unit can change the
order of operations in response to stored information. Peripheral devices include input
devices (keyboards, mice, joystick, etc.), output devices (monitor screens, printers,
etc.), and input/output devices that perform both functions (e.g., the 2000s-era
touchscreen). Peripheral devices allow information to be retrieved from an external
source and they enable the result of operations to be saved and retrieved.
Input Devices
An input device is essentially a piece of hardware that sends data to a
computer. Most input devices either interact with or control the computer in some
way. The most common input devices are the mouse and the keyboard, but there are
many others. The key distinction between an input device and an output device is
that the former sends data to the computer, whereas the latter receives data from
the computer. Input and output devices that provide computers with additional
functionality are also called peripheral or auxiliary devices.
1. Keyboard
Keyboards are the most common type of input device. Before keyboards, interaction
with computers was generally carried out using punch cards and paper tape. Most
English language keyboards use the QWERTY layout for the alphabetic keys, which
are surrounded by number, symbol, function, and other key types. By pressing the
relevant keys, a user can feed data and instructions to the computer.
2. Mouse
A mouse interacts with a computer through a process known as "point and click."
Essentially, when a user moves the mouse on the mouse pad, the pointer moves in a
corresponding direction on the computer's monitor screen. The concept of a
computer mouse has its roots in the trackball, a related pointing device invented in
1946 that used a "roller ball" to control a pointer. Most modern computer mice have
two buttons for clicking and a wheel in the middle for scrolling up and down
documents and web pages.
3. Touchpad
Also known as a trackpad, a touchpad is a common substitute for a computer mouse.
It is essentially a specialized surface that can detect the movement of a user's finger
and use that information to direct a pointer and control a computer. Touchpads were
first introduced for laptops in the 1990s, and it's now rare to find a laptop without one.
4. Scanner
The word "scanner" can be used in a number of different ways in the computer world,
but here I am using it to refer to a desktop image scanner. Essentially, a scanner is an
input device that uses optical technology to transfer images (or sometimes text) into
a computer, where the signal is converted into a digital image. The digital image can
then be viewed on a monitor screen, saved, edited, emailed, or printed.
5. Digital Camera
Digital cameras are used to capture photographs and videos independently. Later,
these photo and video files can be transferred to a computer by connecting the
camera directly with a cable, removing the memory card and slotting it into the
computer, or through wireless data transfer methods such as Bluetooth. Once the
photos are on the computer, they can be saved, edited, emailed, or printed.
6. Microphone
A microphone captures audio and sends it to a computer where it is converted to a
digital format. Once the audio has been digitized, it can be played back, copied,
edited, uploaded, or emailed. Microphones can also be used to record audio or to
relay sounds live as part of a video chat or audio stream.
7. Joystick
Joysticks are commonly used to control characters and vehicles in computer video
games. Essentially, a joystick is a handle that pivots on a base and sends its angle or
direction to the computer as data. Many video gaming joysticks feature triggers and
buttons that can be pressed to use weapons or projectiles in games.
8. Graphic Tablet
Also known as digitizers, graphic tablets are input devices used for converting handdrawn artwork into digital images. The user draws with a stylus on a special flat surface
as if they were drawing on a piece of paper. The drawing appears on the computer
screen and can be saved, edited, or printed. While scanners can only create digital
images from drawings, graphic tablets offer greater control and versatility for artists by
allowing them to see their drawing appear live on their monitor as they create it.
9. Touch Screen
Many devices nowadays use a touch screen rather than a mouse as a way for users
to point, drag, or select options on a screen. As the name suggests, a touch screen is
a touch-sensitive monitor screen that reacts to fingers moving across it. Touch screens
are particularly common in portable devices, such as tablets, palmtops, laptops, and
10. Webcam
Webcams are different from digital cameras in two ways. Firstly, they cannot operate
independently from a computer, and second, they have no inbuilt memory. Although
webcams can capture photographs and videos, they are more often used to livestream videos or facilitate video chats.
Output Devices
What Is an Output Device?
An output device is a piece of computer hardware that receives data from a
computer and then translates that data into another form. That form may be audio,
visual, textual, or hard copy such as a printed document.
The key distinction between an input device and an output device is that an input
device sends data to the computer, whereas an output device receives data from
the computer.
For example, using a microphone to record a podcast is an example of using an input
device. Listening to the recorded podcast through a connected speaker is an
example of using an output device. Both output and input devices are examples of
auxiliary or peripheral devices.
Analyzing the Functionality of a Device
There are four different categories of output device: visual, data, print, and sound.
Each output device example has a specific history, so here I cover specifically how
each device works, when it became a part of technology history, popular brands on
the market selling the device, and a fun fact.
1. Monitor
Mode: Visual
Function: A monitor consists of a screen, circuitry, a power supply, buttons to adjust
screen settings, and a casing that contains all of these components. A monitor
displays data from a computer onto a screen so the user can interact with the data
via a digital interface.
Popular Brands: Acer, Alienware, Apple, Asus, Dell, HP, LG, Lenovo, Samsung
Origin Story: The first monitors used the same technology as early televisions,
relying on a cathode ray tube and a fluorescent screen. This technology was first
utilized for computer monitors in 1965 in the Uniscope 300 machine, which had a builtin CRT display. CRT display lights up a series of dots with a beam on an active part of
the screen. This resulted in a maximum resolution of 1600 by 1200 pixels. LCD (liquid
crystal display) entered the market in 2000 and outsold CRT monitors in 2007.
Nowadays, monitors incorporate flat display technology. Plasma monitors are brighter
than both CRT and LCD and function by illuminating tiny charged gas bubbles, or
plasma, in the screen.
2. Printer
Mode: Print
Function: The function of a printer is to create a copy of whatever is sent from the
computer to the printer. Printers take electronic data sent from a computer and
generate a hard copy.
Popular Brands: Brother, Canon, Epson
3. Headphones
Mode: Sound
Function: Headphones output audio from a computer through two individual
headphones for a single listener. Also known as earphones, headphones allow you to
listen to audio without disrupting other people in the vicinity.
Popular Brands: Sennheiser, JBL, Bose, Sony, Skullcandy
4. Computer Speakers
Mode: Sound
Function: Computer speakers are hardware devices that transform the signal from the
computer's sound card into audio. Speakers create sound using internal amplifiers
that vibrate at different frequencies according to data from the computer. This
produces sound.
5. Projector
Mode: Visual
Function: As its name suggests, this output device "projects" computer images or video
onto a wall or screen.
6. GPS (Global Positioning System)
Mode: Data
Function: GPS is a radio-based navigation system that’s composed of a sender
computer and a receiver. The sender broadcasts signals to 24 satellites that ping to
the sender the exact location of the sender computer in the form of latitude and
longitude coordinates. The satellites use microwave signals to “talk” to the GPS, giving
information on location, vehicle speed, and a number of other pieces of data.
7. Sound Card
Mode: Sound
Function: The sound card controls the output of sound signals, enabling devices like
speakers and headphones to work. The sound card is known as an expansion card,
which means it can be added to the motherboard. Although a sound card is not
essential to a computer's basic functionality, you need one if you wish to play games,
watch movies, listen to music, and use audio and video conferencing.
Popular Brands: Audigy, ASUS, Creative, EVGA
8. Video Card
Mode: Visual
Function: As with the sound card, the video card is an expansion card that slots into
the motherboard. The video card processes images and video, enabling visuals to be
seen on a display. Most computers have basic video and graphics capabilities built
into the computer's motherboard, but for faster, more detailed graphics, a video card
is required.
Popular Brands: NIVIDIA, ASUS, MSI, EVGA
9. Braille Reader
Mode: Print
Function: A braille reader is a peripheral device that enables a blind person to read
text displayed on a computer monitor. The text is sent by the computer to the device,
where it is translated into a braille format and made readable by pushing rounded
pins up through a flat surface. Braille readers are also called braille displays and come
in various sizes. Braille readers come in the form of separate devices from a keyboard
or as part of a keyboard. Most use piezoelectric technology, or electricity generated
by mechanical stress, to create a single line of text at a time in the form of raised
10. Speech-Generating Device (SGD)
Mode: Sound
Function: SGDs, also known as voice output communication aids, generate text to
speech. A user types something and when the command is sent, the SGD reads the
sentence out loud.
What is Digital Data Storage?
Digital data storage is essentially the recording of digital information in a
storage medium, typically by electronic means. The storage device usually enables a
user to store large amounts of data in a relatively small physical space, and makes
sharing that information with others easy. The device may be capable of holding the
data either temporarily or permanently.
Digital data storage devices have many uses. For example, computers usually
depend upon information storage to function. Storage media can also be used to
back up important information (storing digital data can involve durability and
reliability issues, so making independent copies of the information is normally a wise
precaution). Some storage devices are also portable, meaning that they can be used
to transfer information from one computer to another.
Digital data storage media generally fall into one of five categories: magnetic storage
devices, optical storage devices, flash memory devices, online/cloud storage, and
paper storage. I will give one or more examples of each category below.
1. Hard Disk Drive
A hard disk drive (also known as a hard drive, HD, or HDD) can be found installed in
almost every desktop computer and laptop. It stores files for the operating system and
software programs, as well as user documents, such as photographs, text files, and
audio. The hard drive uses magnetic storage to record and retrieve digital information
to and from one or more fast-spinning disks.
2. Floppy Disk
Also know as a diskette, floppy, or FD, the floppy disk is another type of storage
medium that uses magnetic storage technology to store information. Floppy disks
were once a common storage device for computers and lasted from the mid-1970's
through to the start of the 21st century. The earliest floppies were 8-inch (203 mm) in
size, but these were replaced by 5 1⁄4-inch (133 mm) disk drives, and finally a 3 1⁄2 inch
(90 mm) version.
3. Tape
In the past, magnetic tape was often used for digital data storage, because of its low
cost and ability to store large amounts of data. The technology essentially consisted
of a magnetically thin coated piece of plastic wrapped around wheels. Its relative
slowness and unreliability compared to other data storage solutions has resulted in it
now being largely abandoned as a media.
4. Compact Disc (CD)
The compact disc, known for short as a CD, is a form of optical storage, a technology
which employs lasers and lights to read and write data. Initially compact discs were
used purely for music audio, but in the late 1980's they began to be also used for
computer data storage. Initially, the compact discs that were introduced were CDROM's (read only), but this was followed by CD-R's (writable compact discs) and CDRW's (re-writable compact discs).
5. DVD and Blu-ray Discs
The DVD (digital versatile disc) and Blu-ray disc (BD) are formats of digital optical disc
data storage which have superseded compact discs, mainly because of their much
greater storage capacity. A Blu-ray disc, for example, can store 25 GB (gigabytes) of
data on a single-layer disc and 50 GB on a dual-layer disc. In comparison, a standard
CD is the same physical size, but only holds 700 MB (megabytes) of digital data.
6. USB Flash Drive
Also known as a thumb drive, pen drive, flash-drive, memory stick, jump drive, and USB
stick, the USB flash drive is a flash memory data storage device that incorporates an
integrated USB interface. Flash memory is generally more efficient and reliable than
optical media, being smaller, faster, and possessing much greater storage capacity,
as well as being more durable due to a lack of moving parts.
7. Secure Digital Card (SD Card)
A common type of memory card, SD cards are used in multiple electronic devices,
including digital cameras and mobile phones. Although there are different sizes,
classes, and capacities available, they all use a rectangular design with one side
"chipped off" to prevent the card from being inserted into the camera or other device
the wrong way.
8. Solid State Drive (SSD)
A solid state drive uses flash memory to store data and is sometimes used in devices
such as netbooks, laptop, and desktop computers instead of a traditional hard disk
drive. The advantages of an SSD over a HDD include a faster read/write speed,
noiseless operation, greater reliability, and lower power consumption. The biggest
downside is cost, with an SSD offering lower capacity than an equivalently priced
9. Cloud Storage
With users increasingly operating multiple devices in multiple places, many are turning
to online and cloud computing solutions. Cloud computing basically involves
accessing services over a network via a collection of remote servers. Although the
idea of a "cloud of computers" may sound abstract to those unfamiliar with this
metaphorical concept, in practice it can provide tremendous storage solutions for
devices that are connected to the internet.
10. Punch Card
Punch cards (or punched cards) were a common method of data storage used in
the early computers. Basically, they consisted of a paper card with punched or
perforated holes that have been created by hand or machine. The cards were
entered into the computer to enable the storage and accessing of information. This
form of data storage media pretty much disappeared as new and better
technologies were developed.
• Characterized by vacuum tubes started in 1951.
• UNIVAC I (Universal Integrated Automatic Computer)
• UNIVAC first commercially viable electronic digital computer
• It handled alphabetic characters instead of just numbers.
• IBM 701 marked the company’s initial foray into the market
• IBM 650 it was designed as a logical upgrade to the existing punched card
• 1959 marked the invention of transistors
• Faster input-output devices were also developed
• IBM Competitors: Burroughs, UNIVAC, NCR, CDC, and Honeywell, collectively
known as BUNCH
• 1963 marked the successful introduction to the market of minicomputers via Digital
Equipment Corporation’s PDP-8
• 1967 arose the third generation of computer the invention of smaller electronic
circuits called integrated circuits
• IBM’s System 360 the first used computer in this generation
• Integrated circuit was composed of numerous transistors manufactured as a single
• 4004 chip the First Microprocessor introduce by Intel Corporation
• A four bit processor with 2,200 transistors
• 1971 the fourth generation of computers.
• Altair 8800 1975 introduce computing to individuals and small companies
• 1981 IBM grab the lead in microcomputer industry through IBM PC (Personal