The document defines a computer as a device that accepts input, manipulates data based on a program, and provides output. It lists common input devices like a mouse, keyboard, and camera. Output devices mentioned include speakers, headphones, and printers. The central processing unit (CPU) and other internal components like the motherboard, video card, and hard drive are described as processing and storage devices. The document provides examples of different types of computers including laptops, desktops, towers, and supercomputers. It also discusses computer networks and transmission media used to connect devices over local and wide area networks.

2. Definition
A computer is a device that accepts information and manipulates it for some result
based on a program or sequence of instructions on how the data is to be processed.

3. The Four Basic Computer Function
• Input Device
• Output Device
• Storage Device
• Processing Device

4. Examples for Computer
Function
Input Device
Mouse
A mouse consists of a ball or laser that tracks the movement of the device.
The computer is able to register the movement of the mouse and translate it
as movement of the cursor on the screen. A mouse also contain buttons that
allow the user to select objects, move windows or open applications. Many also
include a scrolling wheel to allow for scrolling through long documents or Web
pages.
Camera
This is a small video camera that takes video and inputs it into the computer.
These allow you to record and send small videos or have a video chat with
someone over the Internet.
Keyboard
A keyboard consists of a series of keys that can be pressed to input
commands or letters. These are used to write documents but can be used to
navigate user interfaces in lieu of a mouse.

5. Output Device
Speaker
are speakers sold for use with computers, although usually capable of other
audio uses, e.g. for an MP3 player.
Headphone
are a pair of small loudspeaker drivers that are designed to be worn on or
around the head over a user's ears.
Printer
a machine for printing text or pictures onto paper, especially one linked to a
computer.
Projector
is an optical device that projects an image (or moving images) onto a surface,
commonly a projection screen.

6. Processing Device
CPU
Alternately referred to as a processor, central processor, or microprocessor, the CPU (pronounced sea-pea-you) is
the Central Processing Unit of the computer.
Video Card
Alternatively known as a display adapter, graphics card, video adapter, video board, or video controller,
a video card is an IC or internal board that creates a picture on a display.
Motherboard
alternatively referred to as the mb, mainboard, mboard, mobo, mobd, backplane board, base
board, main circuit board, planar board, system board, or a logic board on Apple computers.
NIC
Short for Network Interface Card, the NIC is also referred to as an Ethernet card and network adapter.

7. FDD
Floppy Disk Drive, also called FDD or FD for short, is a computer disk drive that enables a user to
save data to removable diskettes.
Hard drive
A hard disk drive (sometimes abbreviated as Hard drive, HD, or HDD) is a non-volatile
memory hardware device that permanently stores and retrieves data on a computer.
Super disk
Alternatively referred to as an LS-120 and LS-240, the Super Disk is a disk drive and diskette
introduced by 3M, which later became Imation.
Tape
A magnetically thin coated piece of plastic wrapped around wheels capable of storing data.
A storage component read and writes component state information from a remote database server
or replicates state information to other servers for in-memory stately failover.

8. Super computer
A supercomputer is a computer with a high level of computing performance compared to
compared to a general-purpose computer.
Mainframe computer
(colloquially referred to as "big iron"[1]) are computers used primarily by large organizations for
large organizations for critical applications, bulk data processing, such as census, industry and
as census, industry and consumer statistics, enterprise resource planning, and transaction
and transaction processing.
Minicomputer
a computer of medium power, more than a microcomputer but less than a mainframe.
mainframe.
Microcomputer
a small computer that contains a microprocessor as its central processor.

9. Laptop
A small, portable computer -- small enough that it can sit on your lap. Nowadays, laptop
Nowadays, laptop computers are more frequently called notebook computers.
computers.
Personal computer
It can be defined as a small, relatively inexpensive computer designed for an individual user.
for an individual user. In price, personal computers range anywhere from a few hundred
from a few hundred pounds to over five thousand pounds.
Tower
The case comes with front, back, and top vents and mounts up to five fans.
fans.
Desktop
desktop computer is a personal computer designed for regular use at a single location on or
a single location on or near a desk or table due to its size and power requirements.

10. A computer network is a set of connected computers. Computers on a network are
called nodes. The connection between computers can be done via cabling, most
commonly the Ethernet cable, or wirelessly through radio waves. Connected computers
can share resources, like access to the Internet, printers, file servers, and others. A
network is a multipurpose connection, which allows a single computer to do more.

11. • LAN- A LAN connects network devices over a relatively short distance.
• WAN- A WAN spans a large physical distance. The Internet is the largest WAN, spanning the Earth. A WAN is a
geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN.
• Wireless Local Area Network - A LAN based on Wi-Fi wireless network
technology
• Metropolitan Area Network - A network spanning a physical area larger than a LAN but smaller than a WAN, such
as a city. A MAN is typically owned and operated by a single entity such as a government body or large corporation.
• Campus Area Network - A network spanning multiple LANs but smaller than a MAN, such as on a university
or local business campus.
• Storage Area Network - Connects servers to data storage devices through a technology like Fibre Channel.
• System Area Network - Links high-performance computers with high-speed connections in a cluster
configuration.

12. Transmission Media is a pathway that carries the information from sender to
receiver it is also called Communication channel. Transmission media are the
physical pathways that connect computers, other devices, and people on a
network—the highways and byways that comprise the information
superhighway.

13. • Wired or Guided Media or Bound Transmission Media:
Bound transmission media are the cables that are tangible or have physical existence and are limited by the physical
geography. Popular bound transmission media in use are twisted pair cable, co-axial cable and fiber optical cable.
Coaxial Cable
is a type of electrical cable that has an inner conductor surrounded by a tubular insulating
layer, surrounded by a tubular conducting shield. Many coaxial cables also have an insulating
outer sheath or jacket.
Fiber optic cable
is a high-speed data transmission medium. It contains tiny glass or plastic filaments that carry
light beams. Digital data is transmitted through the cable via rapid pulses of light.
Twisted Pair Cable
is a type of wiring in which two conductors of a single circuit are twisted together for the
purposes of canceling out electromagnetic interference (EMI) from external sources; for
instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk
between neighboring pairs.

14. Microwave Relay
It consists of transmission tower responsible for transmitting or repeating the signal for each
the signal for each hop (the distance is around 30 Kilometers to 50 Kilometers). The
Kilometers). The microwave in Figure uses the line of sight (the received tower can be visual
tower can be visual by the transmitted tower) transmission. The transmission rate can be up
transmission rate can be up to 250M bps.
Satellite
The use of Satellite is to extend the coverage area. Signal is transmitted up and down
between ground stations. The satellite is therefore used as a repeater for re-generating
the signal. Figure shows how it works. Here, a transmit signal is reflected by the satellite
to cover a region on the earth.
• Wireless or Unguided Media or Unbound Transmission Media:
Unbound transmission media are the ways of transmitting data without using any cables. These media are not
bounded by physical geography. This type of transmission is called Wireless communication.

15. • Information is funny stuff. The information for the web
page you are looking at is recorded on a hard disk
inside a computer located in New Britain, Connecticut.
The information was copied from that physical device
to other physical devices perhaps hundreds of times
before it got to your computer where your web
browser is using it to display these words on your
monitor. Clearly information is something different from
the devices used to store and transmit it.
• A computer system consists of both hardware and
information stored on hardware. Information stored on
computer hardware is often called software.
• The hardware components of a computer system are
the electronic and mechanical parts.
• The software components of a computer system are
the data and the computer programs.

16. Major Parts of the Computer
Mouse
Used for making selections. There are two buttons on a mouse. Most actions are performed
using the left mouse button. Some mice have cords and some do not.
Hard drive
The hard drive part of your computer is also called the hard disk.
Display Adapter
Whether a graphic card or part of the motherboard, the display adapter is the component of your
computer that interprets video signal.

17. Motherboard
The motherboard provides connections for all the peripheral (child) devices. It's
devices. It's becoming increasingly common for a motherboard to perform these
perform these peripheral functions without a separate device.
RAM(memory)
Random Access Memory, or RAM, is the part of your computer that is used as
instant memory. RAM is always in use as a temporary location to execute
instructions from your computer.
CPU
The processor, or CPU, of a computer is basically the brains of the computer. The processor
is responsible for interpreting every code it receives from the other computer components,
and making it usable to your operating system.

18. PCI Express x1 slot
PCI slot (2)
Floppy drive controller
PCI Express x16 slot (2)
South Bridge chip
SATA host adapter (4)
PATA host adapter (2)
Mounting holes 24-pin ATX v2.0 power connector
Dual-channel DDR2
memory slots
PCI Express x16
slot (2)
CMCS battery
Socket 775
processor socket
4-pix ATX12 power
connector
Port cluster

19. Power Supply
PS/2 Ports
VGA Video
Audio Jacks
USB Ports
Ethernet LAN Port
Parallel Port
Power Supply Cooling Fan
Case Cooling Fan