Computer Skill II
Module 1
INTRODUCTION TO COMPUTER AND OVERVIEWS
1.0 INTRODUCTION
The twenty century not only brought us to the dawn of the information age, but continuing to bring us rapid changes
in information technology. There is no indication that this rapid rate of change will be slowing – it may undoubted
become perquisite in whatever career a student chooses. The technology revolution changes the way we live and the
way we work, as consumers, as a citizen as a business peoples. It is now in the first world a person sit infront of a
computer and do shopping to the local supermarket, walk through aisles, touch a goods on sale, order the items and
then deliver to the front door step. Some scholars quotes as saying that it will be the delivery’s men job that person
to meet.
.
2.0 IDEA OF INFORMATION SYSTEM
When you think about a microcomputer, perhaps you think just the equipment itself. That is you think of monitor or
keyboard. There is more to it than that. The way to think about a microcomputer is as part of an information system.
What is an Information System and what can it do? Before answering this question, is better to understand what is
system?
A system is any group of components (functions, people, activities, events and so on) that interface with and
complement one another to achieve one or more predefined goals. An information system is defied as a system
which assembles, stores, processes and delivers information relevant to an organization (or to society), in such a way
that the information is accessible and useful to those who wish to use it, including managers, staff, clients and
citizens. An information system is a human activity (social) system which may or may not involve the use of
computer systems.
An Information System “IS” is a generic reference to technology-base system that does two things:
1.
Provide information processing capabilities for an individual or perhaps, an entire company. -The
processing capability refers to the system’s ability to handle and process information (e.g. order
processing)-.
2.
Provides information people need to make better more informed decisions. “IS” provide decision makers
with on demand reports and query capabilities as well as routine periodic reports, (e.g. daily, weekly and so
on) and feedback. “IS” routine make programmed decisions without people being involved.
An information system has five parts; people, procedures, software, hardware, and data.
When you think of a microcomputer, perhaps you think just the equipment itself. That is, you think of monitor or
keyboard. There is more to it than that. The way to think about a microcomputer is as part of an information system.
An information system has five parts; people, procedures, software, hardware, and data.
2.1 PEOPLE
It is easy to overlook people as one of the five parts of a microphone system. Yet that is what microcomputers are all
about – making people, the end users like you, more productive.
2. 2 PROCEDURE
Procedures are rules or guidelines for people to follow when using software, hardware, and data. Typically, these
procedure are documented in manuals written by computer specialists. Software and hardware manufactures provide
manual with their products.
2. 3 SOFTWARE
Software is another name for a program or programs. A program consists of the step-by-step instructions that tell
the computer how to do work i.e. to process data into the form you want. The purpose of software is to convert data
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Computer Skill II
Module 1
(unprocessed facts) into information (processed facts). In most cases, the word s software and programs are
interchangeable. There are two kinds of software: system software and application software.
2.3.1 System Software
System software concentrates on technical aspects of computer system. They deals with operating the computer in
such a way that the user does not need to concentrate on technical matters. Some of the task that are performed with
systems software are:
 Loading the programs
 Checking whether or not the computer has the capacity to load the required program

System software enables the application software to interact with the computer hardware
 Managing all computer resources; storage, input, output, and communication devices
System software can be further classified as operating systems, utilities software, device drivers and
programming languages.
2.3.1.1OPERATING SYSTEM
The most important system software program is the operating system, which interacts with the application software
and the computer hardware. They must be loaded first before any other software because operating systems load and
unload other software, allocates resources for different software, and check whether or not resources to run such
software are available or not. The operating system handles such details as running (“executing”) programs, storing
data and programs, and processing data. Windows 2000 and XP are examples of the best-known operating system
for today’s microcomputer users. Others are Windows 95, 98, NT, Me etc.
2.3.1.2 UTILITIES SOFTWARE
Some operations are common in nearly all computers. These include checking whether or not computer has virus or
not, copying files, managing times in computers, setting appearance and others. Given to the nature there are some
software have been programmed to deal with these operations. The software, which deals with these tasks are known
as utility software.
2.3.1.3 DEVICE DRIVER
Several devices other than standard (keyboard, mouse, and others) can be connected to computer system. These
devices can plotter, joystick, flash memory, new printer, and others, to list a few. In order for these devices to
function, the necessary software to initialize these devices is required. These types of software are known as device
drivers. In fact, all devices connected to the central processing units need their software installed otherwise the
device will not be known or identified as connected to the system.
2.3.1. 4 PROGRAMMING LANGUAGES
Software must be written by programmer. Programmers use programming languages to write these instructions so as
to be executed by computers. A language is a media of communication. Thus a programming language is a media of
communication between a computer and a human being instructing the computer on what to do. Once these
languages have been written, they need to be translated from a human understandable format to a computer
understandable format. The process of translation could be done in two ways; compiling or interpreting.
 Compilation is a process of translating human understandable instructions to computer understandable
instructions all of them at once before execution.
 Interpretation is a process of translating these instructions whenever they are encountered.
For example, if there twenty instructions to be translated, compilers will read all of them and then translate all of
them before executing all of them. An interpreter will read one instruction, translate that instruction, and then
execute. This process will repeat twenty times. In due regard, it is obvious that interpretation is a bit slower that
compiling.
There are several programming languages with different capabilities. Some of these are programming languages are
C, C++, Java, BASIC, Pascal, COBOL, etc. As in common languages, these programming languages have syntax to
be followed with different capabilities in handling input/output, being able to be used on networks, time to load their
programs and so on.
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Computer Skill II
Module 1
2.3.2Application Software
Application software might be described as “end user” software. Application software performs useful work on
general-purpose task such as word processing and data analysis.
There are certain general-purpose programs or basic applications. These programs are widely used in nearly all
career areas. They are the kind of programs you have to know to be considered computer component. One of these
basic applications is a browser to navigate, explore and find information on the internet. The two most widely used
browsers are Microsoft’s internet Explorer and Netscape’s navigator. For a summary of the basic applications see
table 1.1:
TYPE
DESCRIPTION
Word Processor
Prepare written documents
Spreadsheet
Analyze and summarize numerical data
Database Management System Organize and manage data and information
Presentation Graphics
Communicate a Message or persuade other people
Browser
Navigate, explore, and find information on the internet
Information Manager or
Maintain electronic calendars, address books, and to – do list
Organizing software
Table 1.1 Basic Applications.
There are many other applications that are more specialized and widely used within certain career areas. They are
the kind of programs you should know to be truly computer component in the future. One of the most exciting
applications is multimedia, which allows user to integrate video, music, voice, and graphics to create interactive
presentations. For a summary of these specialized applications, see table 1.2
TYPE
Multimedia
DESCRIPTION
Integrate video, music, voice, and graphics to create interactive
presentations
Web publisher
Create interactive multimedia web pages
Graphics programs
Create professional publications: draw, edit, and modify images
Virtual reality
Create realistic three-dimensional virtual or simulated environments
Artificial intelligence
Simulate human though processes and actions
Table 1.2 Specialized applications
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2010
Computer Skill II
Module 1
2.4 HARDWARE
The hardware consists of the equipment: keyboard, mouse, monitor, system unit, and other devices. Hardware is controlled
by software. Microcomputer hardware consists of the system unit, input/output, secondary storage, and communication devices.
Modem to connect to the internet
CD or DVD disk drive to store and
transport large amounts of data
Monitor to display information
Floppy disk drive to store and transport data
System unit to process
data and instruction
Keyboard to input instructions
Mouse to select item
Printer to produce
output on paper
Speaker to display
sounds and music
The block diagram of computer hardware, which consists with five main sections, is shown below:
CPU
PROCESSOR
OUTPUT DEVICE
INPUT DEVICE
MEMORY
BACK UP STORAGE
2.4.1 CENTRAL PROCESSING UNIT (CPU)
The Central Processing Unit often called CPU or the Processor, process data and turn it into information. Under the control of
processor, data is received into memory and then processed, the results which initial held in the memory, either saved to storage
device or output to a suitable device. The functions of processor are:
 To control the sequences of instruction
 To give commands to all parts of the system
 To carryout processing
The processor composed of two main components, Control Unit and Arithmetic and Logic Unit (ALU).
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Computer Skill II
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
Control Unit tells the rest of the computer system how to carryout a program’s instructions. It direct the movement
of electronic signals between memory and ALU. It also direct these control signals between the CPU and output
device.
 Arithmetic and Logic Unit performs two types of operation – arithmetic and logical.
 Arithmetic operations are the fundamental math operations; addition, subtraction, multiplication and division.
 Logical operations consist of comparison. That two pieces of data or more are compared to see whether one is
equal to (=), less than (<), or greater than (>) the other.
2.4.2 MEMORY
Memory is the name given to a group of chips inside the processing unit where data is held whilst processing takes place. The
data held in the memory is instantly available to the computer, unlike backing storage, which has to be accessed on disk or tape.
There are three well-known types of memory chips, RAM, ROM and CMOS.
 RAM (Random Access Memory): these chips hold the program and data that the CPU is presently processing. RAM is
known as temporary or volatile storage, because as soon as the microprocessor is turned off, everything in RAM is
lost. It is also lost if there is a power failure that disrupts the electric current going to the microprocessor. For this
reason, it is a good idea to save your works in progress. That is if you are working on a document or spreadsheet,
every few minutes you should save, or store, the material.
 ROM (Read Only Memory): These chips have programs build into them at the factor. Unlike RAM chips, ROM chips
are not volatile and cannot be changed by the user. “ Read Only” means that the CPU can read, or retrieve, the
programs written on the ROM chip, however, the computer cannot write or change the information or instructions in
ROM. ROM chips typically contain special instructions for computer operations.

CMOS (Complementary Metal-Oxide Semiconductor): These chips provide flexibility and expandability of a
computer system. It contains essential information that is required every time the computer system is turned ON. The
chip supplies such information on the RAM unlike RAM, it is powered by a battery and does not loss its contents
when the power is turned off. Unlike ROM, its contents can be changed to reflect changes in the computer system such
as increased RAM and new hardware devices.
Memory Type
RAM
ROM
CMOS
Use
Program data
Fixed start up instruction
Flexible Start up instruction
2.4.3 INPUT DEVICES
Input devices translate symbol that people understand into symbols that computers can process. They are used to get
data into a computer system and act as an interface between the computer system and the outside world. The ideal input device
would collect all required data accurately, without human in intervention. Competent end users need to know about the
commonly used input devices, including keyboard, mouse, digital camera, microphone, joystick, touch screen, scanner,
trackball, light pen, barcode reader etc.
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Computer Skill II
Module 1
2.4.3.1 KEYBOARD
Keyboard is used to send instructions to the computer and input required information or data. When user presses a key on the
keyboard, it makes certain connections to a chip (IC) inside the keyboard. This chip knows what key has been pressed and
sends a code along the keyboard cable to the processor.
The keyboard has a layout similar to typewriter, but it has some extra keys, they are:
Function key, Return key (ENTER), Spacebar, Alphanumeric key, cursor movement (Navigation key) and Numeric
Key Pad.
The PC keyboard consists of three sections, broadly described below:

FUNCTION KEYS: group of twelve keys on the top (F1, F2, … F12). They have different role for different programs.
Press
F1
F2
F3
F4
F5
F6
F7
F8
F9
F10
F11
F12

To
Get online Help or the Office Assistant
Move text or graphics
Insert an AutoText entry (after Word displays the entry)
Repeat the last action
Choose the Go To command (Edit menu)
Go to next pane or frame
Choose the Spelling command (Tools menu)
Extend a selection
Update selected fields
Activate the menu bar
Go to the next field
Choose the Save As command (File menu)
ALPHANUMERIC KEYS: The large center section that works much like a typewriter
These are the normal letter and number keys, as or a standard typewriter. Upper case letters and the characters over the
numbers are obtained by using SHIFT key.
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Computer Skill II
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NUMERIC KEY PAD: The right group of keys switches function numbers to cursor control. These keys can function
in two ways, depending on the state of the number lock function [Num Lock]. By pressing the Num Lock key, it will
be turned ON and OFF.
Num Lock Indicator ON: With Num Lock lamp lit, these keys will work as number keys, this is useful for data entry,
accounting work and etc.
Num Lock Indicator OFF: With Num Lock lamp not lit, these keys will works as cursor movement keys. The way
they work will mostly depend on the program you are running.
Some Important Keys:
Home
This key is often used to move the cursor to the beginning of a line, screen, or
text.
End
This key used to move the cursor to the end of a line.
Page Up
Page Down
Insert
This key is used to move the cursor to the beginning of a screen display or
text.
This key is used to move the cursor to the end of the screen display or text.
Delete
This key is used to control how next text is inserted into existing text.
Pressing the key will often toggle between insert and overwrite mode. Insert
means that text will be inserted at cursor’s position and the following text
moved over. The overwrite mode will cause text entered at the cursor’s
position to replace what already exist.
This key is often used to delete the character at the cursor’s position.
Enter
This is very important key. It is mainly used in two ways:
1.
Backspace
Caps
Lock
Esc Key
When typing in commands, instruction, and data, you usually have
to press this key to confirm your input.
2. To mark the end of a paragraph, and to move the cursor down to the
next line (new line)
This key is used for deleting the character immediately to the left of the
cursor.
Pressing this key will toggle between capital letter and small letter.
The Esc is usually used in application programs to exit a part of that program
or to undo a change you have made.
2.4.3.2 VOICE INPUT DEVICE
Voice input devices convert a person’s speech into digital code. The most widely used voice-input device is the
microphone. It is now popular for inputting data into word processing or database packages. A microphone is the input device
for such system. This input device when combined with a sound card and appropriate software forms a voice recognition
system. The system enables users to operate microcomputers and to create documents using voice commands.
2.4.3.3 SCANNER
The scanner is used to record images of text, drawings, graphs, or special symbols. The images are converted to digital data that
can be processed by a computer or displaying on a monitor. Scanning devices include the following: Image scanner, Fax
machine, Bar-code readers, Character and mark recognition device.
 The image scanner is simply known as scanner and is used to copy and produce image. The scanner allow user to
take a sheet of paper and copy its contents into the computer, or can be used to capture line of text, logos, hand written
signature, or complex diagrams, charts. The object is placed face down on the scanner glass bed and the capture
software is started, this can be piece of software specially written for that purpose, or can be graphic packages that has
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a capture facility built into it. A bright cold cathode light and a scanning head are mounted on a frame that is able to
travel down inside the scanner chassis. The scanner captures a document’s details one line at a time, since the most
flatbed scanners handle an A4 sheet, the width of the scanning area is a minimum of 8.27”, while the most models
have up to 8.5” scanning width.
Fax machine: This device scans the image of a document to be sent. The light and dark areas of the image are
converted into a format that can be sent electronically over telephone lines. The receiving fax machine converts the
signals back to an image and recreates it on paper
2.4.3.4 JOYSTICK
The joystick is the most popular input device for computer games. You can control game actions by varying the pressure,
speed, and direction of joystick. Additional controls such as buttons and triggers are used to specify commands or initiate
specific actions.
2.4.3.5 TOUCH SCREEN
A touch screen is a particular kind of monitor screen covered with a plastic layer. Behind this layer are crisscrossed invisible
beams of infrared light. This arrangement enables someone to select actions or commands by touching the screen with a finger.
Touch screens are easy to use, especially when people need information quickly. They commonly used at automated teller
machine (ATM), information centers, restaurants, and department stores.
2.4.3.6 MOUSE
A mouse controls a pointer that is displayed on the monitor. The pointer usually appears in the shape of an arrow. It frequently,
however, changes shape depending on the application. The standard mouse has a ball on the bottom and is attached with a cord
to the system unit.
2.4.3.7 LIGHT PEN
A light pen is a light sensitive pen-like device. The light pen is placed against the monitor. This closes a photoelectric circuit
and identifies the spot for entering or modifying data. Engineers, for example, use light pens in designing anything from
microprocessor chips to airplane parts.
2.4.3.8 DIGITIZER
A digitizer is a device that can be used to trace or copy a drawing or photograph. The item to be copied is placed on a flat
digitizer tablet. A special stylus connected to a computer is then used to trace the item. As the stylus moves from one position
to another, the computer records its position on the computer records its position on the digitizing tablet. After the item has
been traced, its image can be displayed on the screen, printed out on a paper, or stored on the computer system for later use.
Digitizers are often used by designer, architects, and engineers.

DIGITAL CAMERA
Digital cameras are similar to traditional cameras except that images are recorded digitally on a disk or in the camera’s
memory rather than on film. You can take a picture, view it immediately, and even place it on your own web page,
within minutes. Although faster than traditional photography, digital camera prices are typically higher.

DIGITAL VIDEO CAMERAS
Unlike traditional video cameras, digital video cameras record motion digitally on a disk or in the camera’s memory.
Compared to traditional video cameras, the image quality is better and the price is higher. A digital video camera can
also double as digital camera by capturing still digital image. With their costs declining, digital video cameras are
becoming more and more popular with businesses and home users.
2.4.4 OUTPUT DEVICES
Output devices convert machine-readable information into people readable form. Data that is input to and then processed by
the computer remains in machine-readable form until output devices make it people-readable. Examples of output devices are;
monitor, printer, plotters, speakers, etc.
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Computer Skill II
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2.4.4.1 MONITORS
The most frequently used output device is the monitor. Two important characteristics of monitor are size and clarity.
 A monitor’s size is indicated by the diagonal length of its viewing area. Common sizes are 15, 17, 19, and 21 inches.
Lager monitors have the advantage of displaying more information at one time; however, they are more expensive.
 A monitor’s clarity is indicated by its resolution, which is measured in pixels. Pixels are individual dots or “picture
elements” that form images on a monitor. For a given size monitor, the greater the resolution (the more pixel), the
better the clarity of the image. For a given level of clarity, larger monitors require a higher resolution (more pixels).
To indicate a monitor’s resolution capabilities, several standards have evolved. The most common today are SVGA, XGA,
SXGA and UXGA.
 SVGA stands for Super Video Graphics Array. It has a minimum resolution of 800x600 pixels. It is used primarily
with 15-inch monitors.
 XGA stands for Extended Graphics Array. It has a resolution of up to 1,024 by 768 pixels. It is popular standard today,
especially with 17- and 19-inch monitors.
 SXGA stands for Super Extended Graphics Array. This standard has a resolution of 1,280 by 1,024 pixels. It is
popular with 19- and 21-inch monitors.
 UXGA stands for Ultra Extended Graphics Array. UXGA is the newest and highest standard. It is primarily used for
high-end engineering design and graphic arts.
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© The State University of Zanzibar
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Computer Skill II
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2.4.4.2 PRINTERS
Printer is one of the output devices that print out data in hardcopy. There are several kinds of printer with different ways of
working. Some can only print text. Others can print text and graphics. Black and white printers are more common, while color
printers are more expensive and often slower. Printers work at various speeds. Characters printers print one character at a time.
Line printer prints one line at a time and page printers print a page at a time. Printers are classified into two main groups;
Impact and non-impact printers.
PRINTERS
IMPACT PRINTER
Dot
Matrix
Daisy
Wheel
NON IMPACT PRINTER
Chain
InkJet
Laser
Thermal
(a) Impact Printers
These printers print by hitting an inked printer ribbon against paper.
 Dot Matrix Printer is an line printer, it got heads consists of small pins between 9 and 24, a 24 pins will produce a
better quality print the dot are smaller and close together. When print head moves across the page a selected pin strike
the ribbon and make a dot on the paper.
 Line or Chain Printer, again, is an impact printer most common with mainframe computer installation, the character
are embossed on the edge of the drum, which revolves at high speed so that each character can be presented
underneath the hammer in a fraction of a second. It got the same characteristics with the Dot-matrix Printer.
 Daisy Wheel printer is old printer, which consists of 90’s petal daisy wheel, which rotates to print the correct character
by means of hammer striking the petal against the ribbon. It got the same characteristics with the Dot-matrix printer
except that the daisy wheel printer can’t produce graphics output and can’t get other style of fonts unless you change
the wheel for style required, it is a character printer.
Advantages:
 Printer is cheap in price when you tally with others type of printer InkJet/Laser printer
 It can print multiplayer form
Disadvantages
 Printer takes long time to print, is about 10 to 200 character per second.
 Printer got low resolution in graphics
 Low quality of print mark
 It make noisy and slow when it print a document
 Quite hard to change cartridge
(b) Non-Impact Printers
Printers squirt or press ink into paper, most printers use ink cartridge or toner which can be replaced when they run out. Toner
is powered ink. Printed images usually made up of thousands of tiny dots. The smaller the dots, the sharper the clearer the
printout. The sharpness of the printout is called the print resolution.
Non-impact printers are those, which its mechanism of operation is different with impact printers.
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Computer Skill II
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 Inkjet Printer
Produce an image character by spraying ink at the paper. It is a line printer. They are available to print in color or black and
white. Although the initial cost of an ink-jet printer is set attractively low, the cost of the consumables, which are mainly the ink
cartridges, can be high and many manufactures make more money out of selling the consumables than from the sale of the
actual printer.
 Laser Printer
Use a process similar to a photocopying machine, the laser printer represent the high technology including the laser imaging.
Laser printers are the fastest printers, (typically 10 pages per minutes or more) and are available in black and white or color.
They use laser beam to produce images with excellent letter and graphics quality.
 Thermal Printers
A thermal printer uses the heat elements to produce images on heat-sensitive paper. Originally these printers were used in
scientific in labs to record data. Color thermal printers are not as popular because of their cost and the requirement of specially
treated paper. They are more special-use printer that produces near-photographic output. They are widely used in professional
art and design work where very high quality color is essential.
Advantages and disadvantages of non-impact printers:
Advantages
 It is quite when it print and print fine resolution character output.
 Print at a high speed when it compared with impact printers
 Print large volume, since they are page printer. Laser printers are able to print a page at a time.
 Laser printer produce high quality text and graphics.
Disadvantages
 It is expensive printer
 They are quite complex, so repair bills can be high.
2.4.5 BACKING STORAGE (SECONDARY STORAGE)
Storage devices are all devices that store data permanently in computer system. Baking up is the creation of copies of program
and data so that if they are lost they can be recreated. There are four main storage devices; magnetic tapes, magnetic disk,
optical disks and flash memory (the recent technology). Secondary storage is storage outside the processor.
 MAGNETIC TAPES
Magnetic tapes stores data in a spool of plastic tapes. They use the same technology used in audio and video cassettes. These
devices have capacities of several megabytes. Organizations use magnetic tapes, in many circumstances, as for backup because
they can be kept away from the computer system.
 MAGNETIC DISKS
Magnetic disks incorporate floppy disks and hard disk.
 Floppy disk have capacities of 1.44 MB (Megabytes) and are easy to move from one computer to another, while
 Hard disks can go as far as few GB (gigabytes) to TB (Terabytes). Hard disks are normally securely fixed within a
computer system case.
In order to further increase the storage capacity, several hard disks can be linked together using the technology known as
redundant array of independent disks (RAID). These are magnetic hard disk from several microcomputers for providing large
and fault tolerant storage capacities.
 OPTICAL DISKS
Optical disks involve the technology of using laser light to read and write the data in the storage devices. The most
common devices are Compact Disks (CD) and Digital Versatile Disks (DVD) formerly (Digital Video Disk). A simple
scratch on CD or DVD may make it unworkable; therefore, they must be handled with care because they are not covered.
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Computer Skill II
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 COMPACT DISKS (CD)
CD could be recordable (CD-R) or rewritable (CD-RW). CD-R can be written once while CD-RW can be written, erased
and be rewritten. Nowadays the CD is widely used as a means to store and distribute data and information. It can stores up
to 750MB of data. It is thus ideal as a medium for distributing large files, multimedia games and software packages.
 DIGITAL VIDEO DISKS (DVD)
DVD was originally said to stand for digital video disc, and later for digital versatile disc. DVC can hold twenty times the
capacity of CD. DVD is an optical disc technology with a 4.7GB (gigabytes) storage capacity on a single-sided, onelayered disk, which is enough for a 133-minute movie. DVDs can be single- or double-sided, and can have two layers on
each side; a double-sided, two-layered DVD will hold up to 17GB (gigabytes) of video, audio, or other information. This
compares to 650MB (megabytes) of storage for a CD-ROM disk.
 FLASH MEMORY (Stick Memory, USB Storage device)
Over the recent years, memory sticks (flash memory) have been introduced. Memory sticks resembles to a pen. One can
store around 256MB (megabytes) and put memory stick in his pocket without distorting data to a great extent, like with
floppy diskettes or optical disks. Like the floppy diskette you can read and write to a thumb drive but it has the advantage
of storing much more data than a diskette. They have the capacities 16MB, 32 MB, 64 MB, 128 MB, 256MB, etc. are
common.
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Computer Skill II
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2.5. Data
Data represent unstructured facts about events, objects, or people. It is the raw material for information, in which
data have been collected and processed into a meaningful form. The essential difference between data and
information, therefore, is that data are not interpreted whereas information has a meaning and use to a particular
recipient in a particular context and can be used for decision making. Information comes from selecting data,
summarizing it, and presenting it in such a way that it is useful to the recipient.
Data processing or information processing
In general, Data Processing is the process that involves transformation of data into information or knowledge
through classifying, sorting, merging, recording, retrieving, computing, transmitting, or reporting. For this view, a
data processing can be manual or computer based.
The operations performed upon data in accordance with strictly defined procedures, such as recording and
summarizing the financial transactions of a business. In automatic or electronic data processing the
operations are performed by a computer. In distributed data processing some or all of the operations are
performed in different locations at computer facilities connected by telecommunications links.
In the context of data processing, data are defined as numbers or characters that represent measurements
from observable phenomena. A single datum is a single measurement from observable phenomena.
Measured information is then algorithmically derived and/or logically deduced and/or statistically
calculated from multiple data. (Evidence). Information is defined as either a meaningful answer to a query
or a meaningful stimulus that can cascade into further queries.
The processing is usually assumed to be automated and running on a computer. Because data are most useful when
well-presented and actually informative, data-processing systems are often referred to as information systems to
emphasize their practicality. Nevertheless, both terms are roughly synonymous, performing similar conversions;
data-processing systems typically manipulate raw data into information, and likewise information systems typically
take raw data as input to produce information as output.
(1) Processing information by machines. Data processing was the first name used for the information technology
business, and it is still used as an umbrella title. In the early days, it meant feeding punch cards into tabulating
machines. Then computers followed. See preprocessing. See also information processing cycle.
(2) Processing data/information. In this context, it refers specifically to processing the actual data of the business
(raw number crunching) in contrast to the processing overhead of the operating system and networks. In many
instances, the computer does very little data processing compared to the processing required by the operating
system, graphical interface and other infrastructure components.
Information Processing Cycle
The sequence of events in processing information, which includes (1) input, (2) processing, (3) storage and (4)
output. The input stage can be further broken down into acquisition, data entry and validation. The output stage can
also be further divided into interactive queries and routine reports. A fifth stage is often attributed to this cycle,
which is the archiving or deletion of unwanted data.
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© The State University of Zanzibar
2010
Computer Skill II
Module 1
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