Computer Hardware

Definition

Classification

Input Devices

Output devices

Keyboard

Joystick

Mouse

Scanner

Microphone

Storage Devices

Memory

Barcode reader

Digital camera

Touch screen

Light pen

Touch pad

Captures images from photographs, magazines, books etc.

Stores them in the computer in a digital form

Images can be edited, displayed on the screen or inserted in the documents

Allows the user to enter letters, numbers and special symbols into the computer

Main input device to communicate with the computer

Hand-held device used to control the movement of the cursor

Two or three buttons that allow the computer user to make selection in the menu, draw graphics or open files


Changes audio signals into electronic signals which are translated into digital form by the sound card

Allows the user to input audio into computer

Includes buttons called triggers

Mainly used for computer games

A pointing device with a vertical lever mounted on a base

Information is used by the computer to print bill for the customer

Reads the bar code printed on products that represents product code, description and price

Used to capture pictures and store them in a digital form

Can be downloaded to computer for editing, viewing or inserting in documents

Pressure sensitive display screen

Used to interact with the computer by touching the pictures or words with fingers

It is an input device on laptops and some keyboards to move a cursor with finger

The cursor moves in the same direction as the user's finger does

in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.

It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy.

System Unit

Registers

ALU

Microprocessor

Motherboard

Control Unit

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Contains microprocessor, main memory, expansion cards, many IC chips, connectors and other electronic components

It is the main circuit board inside the system unit and all the input and output devices are connected to the motherboard

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Loads programs into memory and executes them

Consists of very complicated circuits and Controls the operations of all the operations of the computer

Performs all the calculations and comparisons

Arithmetic unit performs operations like Addition, subtraction, multiplication and division and logical unit performs logical operations which include comparisons of numbers or alphabets

Controls all the activities on the computer

It is the main chip on the motherboard

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Hard disk

DVD

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Small memory units in the microprocessor

Temporarily store some information during the execution of the program

Some common registers are Cash registers, Instruction register etc

Monitor

Printer

Plotter

Speaker

Memory Card

A magnetic storage device used to store computer data

Fixed inside the computer casing

Storage capacity of hundreds of gigabytes

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Has more storage capacity then the CD

installed in the computer to read data from or write data to a DVD

A small storage device having storage capacity of few gigabytes

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Available in different sizes

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RAM

Cache Memory

ROM

High speed memory installed on the motherboard

Information can be read from or written into it

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A very small amount of extremely fast memory

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Faster and more expensive than RAM

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Refers to physical parts of a computer

A single IC chip installed on the motherboard