An electronic device which is

capable of receiving information

(data) in a particular form and of

performing a sequence of operations

in accordance with a predetermined

but variable set of procedural

instructions (program) to produce a

result in the form of information or

signals.

INPUT DEVICES

AND

OUTPUT DEVICES

In computing, an input device is a

peripheral (piece of computer hardware

equipment) used to provide data and

control signals to an information

processing system such as a computer or

other information appliance. Examples

of input devices include keyboards, mice,

scanners, digital cameras and joysticks.

A computer keyboard is one of the primary input devices used with a computer that looks similar to those found on electric typewriters but with some additional keys. Keyboards allow the user to input letters, numbers, and other symbol into a computer that often function as commands. The following image shows a saitek keyboard with indicators pointing to each of the major key sections of a keyboard.

A computer mouse is an input device that

is most often used with a

personal computer. Moving

amouse along a flat surface can move the

on-screen cursor to different items on the

screen. Items can be moved or selected

by pressing the mouse buttons

An input device that utilizes a light-

sensitive detector to select objects on

a display screen. A light pen is similar

to a mouse, except that with a light

pen you can move the pointer and

select objects on the display screen

by directly pointing to the objects with

the pen.

A device used in sound

reproduction systems for converting sound into

electrical energy, usually by means of a

ribbonor diaphragm set into motion by the

sound waves. The vibrations are converted int

o the equivalent audiofrequency electric curre

nts.

A cam, homecam, or Webcam is a video camera, usually attached directly to a computer, whose current or latest image is requestable from a Web site. A live cam is one that is continually providing new images that are transmitted in rapid succession or, in some cases, in streaming video. Sites with live cams sometimes embed them as java applets in Web pages. Cams have caught on; there are now several thousand sites with cams

Electronic or electromechanical

equipment connected to a computer

and used to transfer data out of the

computer in the form of text, images,

sounds or other media to a display

screen, printer, loudspeaker or

storage device.

A computer monitor is an electronic

device that shows

pictures. Monitors often look similar to

televisions. The main difference between

amonitor and a television is that

a monitor does not have a television tuner

to change channels.Monitors often have

higher display resolution than televisions.

A printer is a piece of hardware for

a computer. It is a device which allows a

user to print items on paper, such as

letters and pictures. It can also work with

digital cameras to print directly without the

use of a computer. To do its work, a printer

must be connected to a computer.

The plotter is a computer printer for

printing vector graphics. In the

past, plotters were used in applications

such as computer-aided design, though

they have generally been replaced with

wide-format conventional printers.

A plotter gives a hard copy of the output.

It draws pictures on paper using a pen.

Speaker is defined as an electrical device

used to make sound or music louder. An

example of speaker is how music is

listened to in a car. Thedefinition of

a speaker is a spokesperson or a person

giving a speech. An example of speaker is

the person who people have gathered

around to hear talk about something.

Sometimes referred to

as earphones, headphones are a

hardware device that either plugs into

your computer or your speakers and

allow you to privately listen to audio

without disturbing anyone else.

Bus is an electrical pathway through which bits are transmitted between the various computer components. In other words, the bus is the channel, which lets the parts of a computer, communicates with each other. A bus is classified by name according to its function.

Communication bus can be classified into three categories

1. Address bus2. Data bus &3. Contol bus

A collection of wires connecting the CPU with main memory that is used to identify particular locations in main memory. The width of the address bus determines how many unique memory locations can be addressed. Modern PCs and macintoshes have as many as 36 address lines, which enables them theoretically to access 64 gb main memory. However, the actually amount of memory that can be accessed is usually much less than this theoretical limit due to chipset and motherboard limitations.

A collection of wires through which data is

transmitted from one part of a computer to

another. We can think of a bus as a highway on

which data travels within a computer. When used

in reference to pesonal computers, the

term bus usually refers to internal bus. This is a

bus that connects all the internal computer

components to the CPU and main memory.

There's also an expansion bus that enables

expansion boards to access the CPU and

memory.

The physical connections that carry control

information between the CPU and other devices

within the computer. Whereas the data

bus carries actual data that is being processed,

the control bus carries signals that report the

status of various devices. For example, one line

of the bus is used to indicate whether the CPU is

currently reading from or writing to main memory.

Computer ports are connection points or

interfaces with other peripheral devices.There

are two main types of computer ports: physical

and virtual.Physical ports are used for connecting

a computer trough a cable and a socket to a

peripheral device. Here are some ports:-

1. Parallel Port

2. RJ45 Port

3. RJ11 Port

4. USB Port

5. Serial Ports

A parallel interface for connecting an external device such as a printer. Most personal computers have both aparallel port and at least one serial port. On PCs, theparallelport uses a 25-pin connector (type DB-25) and is used to connect printers, computers and other devices that need relatively high bandwidth.

An Registered Jack 45 (RJ-45) port is a data port often found on computers, network routers, switches and hubs. It is commonly used for an Ethernet or serial connection with an 8 position 8 conductor (8P8C) jack. In the past, some modems and telephones included a port that used a true RJ-45 jack. Although the 8P8C jack is not identical to the RJ-45, the data port commonly retains the name.

A "port" is an IT term for socket. The

RJ11 port is found in millions of homes

and businesses all over the world. It is

the phone socket. Although, strictly

speaking, "ports" are only found on

computers, the same socket can be

found on telephones, fax machines and

in wall sockets.

Short for Universal Serial Bus, an

external bus standard that supports

data transfer rates of 12 Mbps. A

single USB port can be used to

connect up to 127 peripheral devices,

such as mice, modems, and

keyboards. USB also supports Plug-

and-Play installation and hot

plugging.

A serial port is a general-purpose

interface that can be used for almost

any type of device, including

modems, mice, and printers

(although most printers are

connected to a parallel port).

A memory card (sometimes called a flash memory card or a storage card) is a smallstorage medium used to store data such as text, pictures, audio, and video, for use on small, portable or remote computing devices.

There are many types of memory cards available in the market.These are:

Smart Media Cards Multimedia Cards Compact Flash Extreme Digital Cards Secure Digital Card Memory Stick

A SmartMedia card (originally called

a solid-state floppy disk card, or

SSFDC) is a

memory card developed by Toshiba

that uses flash memory to store data

and to make it portable among

devices, such as digital cameras,

personal digital assistants (PDAs),

and other handheld devices

xD Picture Card. (EXtreme

Digital PictureCard) An earlier flash

memory card used in digital cameras.

Introduced in 2002 by Fuji and Olympus,

the xD cards were the smallest flash

memorycards on the market until the Mini

SD card was announced in 2003.

The MultiMediaCard (MMC) is a

memory cardstandard used for solid-state

storage. Unveiled in 1997 by SanDisk and

Siemens AG, it is based on Toshiba's

NAND-based flash memory, and is

therefore much smaller than earlier

systems based on Intel NOR-based

memory such as CompactFlash.

An SD Card (Secure Digital Card) is an

ultra small flash memory carddesigned to

provide high-capacity memory in a small

size. SD cards are used in many small

portable devices such as digital video

camcorders,digital cameras, handheld

computers, audio players and mobile

phones.

CompactFlash (CF) is

a flash memory mass storage device

used mainly in portable electronic

devices and was the

first flashmemory card. The format

was specified and the devices were

first manufactured by SanDisk in

1994.

Memory Stick is a type of flash

memory developed by Sony. It is used

to store data for digital cameras,

camcorders, and other kinds of

electronics. Because Memory Stick is a

proprietary Sony product, it is used by

nearly all of Sony's products that use

flash media