What is a computer?
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A computer is a programmable
electronic device that accepts data and
performs operations on that data.
Types of Computers
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Notebook: Portable computer
Desktop: Used at a single location
Mainframe: supports hundreds of users
simultaneously
Supercomputers: performs complex
calculations rapidly (used by scientists
and engineers)
What is the Motherboard?
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This is the main circuit board that connects all the
other internal components, such as the CPU, RAM,
Expansion cards and memory.
What is the Microprocessor?
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Is the brains of the computer
Controls all functions of the computer
Performs arithmetic and logic operations
It is also called the CPU, Central Processing Unit
The speed of the processor is measured in gigahertz
(GHz)
Information Processing Cycle
The information processing cycle refers to the basic
tasks a computer follows when presented with data.
A computer performs 4 major functions
1.
2.
3.
4.
Input: Enter data into the computer
Storage: Save data, programs, or output for future
use
Process: Perform operations on the data
Output: Present the results
Step 1: Input
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A computer takes in information, known as input.
Input devices are devices used to enter
information or instruction into the computer
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Keyboard
Mouse
Microphone
Scanner
Digital Camera
Stylus
These are
also known
as
peripheral
devices
Step 2: Storage
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A computer stores the information in order to
remember it. It uses the following storage
devices:
  Hard Drive (main storage device)
  Optical drive (Compact disks)
These are also
  USB drive (flash disks)
peripheral
devices
  DVD/Blu-ray disks
Bytes
What is capacity?
  Number of bytes (characters) a storage medium can hold
Kilobyte (KB)
1 thousand
Megabyte (MB)
1 million
Gigabyte (GB)
1 billion
Terabyte (TB)
1 trillion
Petabyte (PB)
1 quadrillion
Exabyte (EB)
1 quintillion
Zettabyte (ZB)
1 sextillion
Yottabyte (YB)
1 septillion
Step 3: Processing
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A computer looks at the data and reacts to it.
  This is known as processing
Step 4: Output
A computer sends processed data out of the
computer. It uses the following output
devices:
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Monitor
Printer
Speakers
Hardware
The Physical parts of the computer that you can
actually touch
Software
What is software:
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Å set of instructions that tell the hardware what to do.
Also called a program
There are two types of software:
Application software:
Programs used to
complete tasks
Examples:
-Microsoft Office
Adobe Photoshop
System software: coordinates instructions
Between software and Hardware.
Examples:
-Operating system
-Utility programs
File Name Extensions
File Name Extensions contd.
Operating Systems
  The OS is a large program made up of many smaller
programs that control how the CPU communicates with
other hardware components.
  Apple Macintosh uses
  PC and compatibles
the Macintosh operating
use the Windows
system (Mac OS X).
operating system.
More expensive and has
Windows 7 is the latest
fewer software available
version
What does the OS do?
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Provides a user interface in order to
interact with the computer
Manages the CPU
Manages memory and storage
Manages hardware and peripheral
devices
MAC User Interface
Windows User Interface
Types of Memory
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Random Access Memory (RAM)
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Read-Only Memory (ROM)
Random Access Memory
Machines running
windows 7 must have
at least 1GB of RAM.
For peak
performance, it is
recommended that
you have 2GB
Read-Only Memory
Storage
What is storage?
  Holds data, instructions, and information for future use
  Storage medium is physical material used for storage
  Also called secondary storage
Storage: Hard Drive
What is a hard drive?
  The primary device for
permanent storage
  It is a High-capacity
storage stored inside
your computer (60 to 500
GB)
Windows 7
requires at least
20GB of hard
drive capacity. hard disk mounted
in system unit
Storage: Optical Disks
What is an Optical Disk?
  Disks that use laser to store
and read data
  Data is saved to Compact
disks (CDs), Digital Video
disks (DVDs), or Blu-ray
disks (BDs)
  All forms of optical media
come in pre-recorded,
recordable, and re-writable
forms
Storage: CD-ROM
What is a CD-ROM?
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Compact disc read-only memory
Cannot erase or modify contents
Typically holds 700 MB of data
Commonly used to distribute multimedia and complex
software
It’s an optical disk- uses lasers to read data
Storage: Compact Discs
What are CD-Rs and CD-RWs?
  Optical disks that use laser to read/write data
  Typically holds 700 MB
CD-R (compact disc-recordable)
Cannot erase
disc’s contents.
You can only write
Onto it once
CD-RW (compact disc-rewritable)
Erasable disk you can
Write on
Multiple times
Storage: DVD Disks
What is a DVD-ROM (digital versatile
disc-ROM or digital video disc-ROM)?
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Stores databases, music,
complex software, and movies
It can hold up to 4.7 GB of data
Storage: Blu-ray Disks
What is a Blu-ray (BDs) disks?
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Stores databases, music,
complex software, and movies
Blu-ray are currently the fastest
optical devices on the market
It can hold up to 50 GB of dada,
thus allowing to store high
definition (HD) movies.
Storage: Flash Drive
What is a USB Flash Drive?
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Plugs in a USB port on a
computer or mobile device
An alternative way of storing
portable data
Functions as a portable hard
drive
Sometimes referred to as USB
drive, thumb drive or jump
drive
Storage capacities up to 64 GB
May eventually make the
floppy disk obsolete
Storage: Flash Memory Card
What is a Flash Memory Card?
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Tiny, removable memory
cards that let you transfer
digital data between your
computer and devices such as
digital camera, PDA’s, video
cameras, and smart phones
It is the size of a postage
stamp
It can hold up to 32 GB of
data
What is a Port?
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A port is a place through which a device can attach to a
computer so that data can be exchanged.
Many ports are located on the back of a computer
The most popular port is USB, connecting a wide range of
devices such as keyboards, mouse, printers, external hard drives,
smart phones, digital cameras and more.