Input Devices and their major functions

Input Devices are electronic hardware devices, which are used to give data/instruction to the pc. A data input device sends data into computer’s main memory or CPU and auxiliary storage.

Some major functions of input devices are:

  • It accepts data from the user or outside the environment.
  • It converts user understandable form of data into binary code that is understandable to the computer.
  • It sends data & instructions in binary form to the computer for further processing.
Input Devices

The computer only understands binary data in binary format (01010). Hence, input devices are responsible for sending the data that our computer will easily understand.

Following are a number of the important types of input devices that are utilized in a computer.

Types of Input Devices

What is Computer Keyboard?

The keyboard is the most popular data input device in any computer system. It converts the key data to electronic signals i.e. binary digital form.

The layout of the keyboard is like that of a standard typewriter of type QWERTY. It consists of a group of typewriter-like keys that enable the entry of data into the PC.

Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys also are available for Windows and Internet. Although there are some additional keys provided for performing additional functions.


Types of keys in a Keyboard

  1. Alphanumeric Keys : These keys include the letter keys (A-Z) and numbers keys (0/9).

3. Function Keys: The twelve function keys are present on the keyboard on the top. Each function key features a unique meaning and is employed for a few specific purposes.

4. Control keys: These keys provide cursor and screen control. e.g. Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc), etc.

5. Special Purpose Keys: Keyboard also contains some special purpose keys like entering, Shift, Caps Lock, Number Lock, Space bar, Tab, and Print Screen, etc.

Types of keyboards

A keyboard may be a portable, wired, or wireless device that contains all the alphabets, numeric, symbols, and special characters, which is employed for entering input files into a laptop/personal computer system.

Keyboards are classified supported by the dimensions and their mode of usage. Those types are discussed below:

Multimedia Keyboard

The keyboard that has all multimedia buttons is named a multimedia keyboard. The buttons include play, pause, previous, next, volume up, volume down, mute and special buttons to launch media. Also, a button to launch a browser, my computer, calculator is out there.

Mechanical Keyboard

The primitive keyboard which uses physical buttons for every key’s called a mechanical keyboard. It makes noise when each key’s pressed. A button is pushed down and an electrical signal is shipped to the pc device which then shows the characters.

Wireless Keyboard

Bluetooth, IR technology, or Radio-frequency is employed to attach the keyboard to the pc device. These keyboards are lightweight and battery-powered. These keyboards should have a transmitter and trans-receiver.

Transmitter sends the strokes from the keyboard as radio waves which are received by trans-receiver kept near parent device (Computer).

Virtual Keyboard

The keyboard utilized in smartphones is named a virtual keyboard. This keyboard appears when needed and disappears when typing is completed. this will be automatically set as per need.


The mouse is again the most popular data input device which controls the cursor or pointer while working on a computer screen/monitor.

Mouse: Input Devices

Generally, the mouse contains a right button, a left button, and a wheel present between the buttons. Mouse performs various functions like opening a file or program, select menus move icons, size windows, start programs, and close windows, etc.

Types of mouse

Mechanical Mouse

A mechanical mouse features a rubber or metal ball on its underside which will appear in all directions.

Once we move the mouse then the mouse’s ball roll and sensors that are embedded inside identify the motion and move the cursor on the screen accordingly. These days, the mechanical mouse has been replaced with the Optical mouse.

It is a little palm-size box with laser light at its base, which senses the movement of the mouse and sends corresponding signals to the CPU. It allows us to regulate the pointer during a graphical user interface(GUI).

Optical Mouse

The optical mouse is a data input device, that uses laser light to detect mouse movement. It uses advanced technology like LED (light-emitting diode), optical sensor, and other DSP (digital signal processing) rather than the rubber ball mechanical mouse.

Optical mice haven’t any mechanical moving parts and no mousepads are required. Using process is when the mouse is moved, laser rays hit the surface and supply the direction to the pointer on the screen.

Other types of Mouse present in the Market:

  • Infrared Frequency Cordless Mouse, Trace ball Mouse, Stylus Mouse, 3D Mouse, Laser Mouse, Track Point Mouse, Gaming mice


The joystick is additionally a pointing or a data input device, which looks like a special remote having a spherical ball at both lower and upper ends. The lower spherical ball moves during a socket in any direction.

Functions are almost like that of a mouse. it’s mainly utilized in Computer-Aided Designing (CAD) and playing computer games.


Light Pen

The Light Pen (which looks like a pen) is a pointing device that can be used to pick a menu item or draw on the computer screen.

A photocell and an optical device are enclosed in a narrow tube. When the tip of the pen is passed over the display screen and the button is pressed, the photocell sensing element detects the screen position and sends the appropriate signals to the CPU.

Track Ball

A trackball is a data input device that’s mostly utilized in a notebook or laptop pc, rather than a mouse. it’s a ball that’s half inserted and by moving fingers on the ball, the pointer is often moved.

Since all parts of the device aren’t moved, It requires less space than a mouse. A trackball comes in various shapes sort of a ball, a button, or a square.



The scanner is a data input device, which inputs images or text printed on paper into a computer-readable format by digitizing a picture/text. it’s used when some information is out there on paper and it’s to be transferred to the hard disc of the pc for further editing or manipulation.

In short, it converts Hard Copy documents or images into softcopy (digital format)


The microphone is a data input device to input sound/voice which is then stored in a digital form.

The microphone is employed for various applications like adding sound to a multimedia presentation or for mixing music. Sometimes it’s abbreviated as mike. The information recorded by the microphone is stored within the computer and played back later.

Microphone: A sound input device

Magnetic Ink Card Reader (MICR)

MICR is a data input device that’s generally utilized in banks as there is an outsized number of cheques to be processed a day. The bank’s code number and cheque number are printed on the cheques

It uses a special sort of ink that contains characters. When it passes through the MICR reader, the particles of magnetic material are readable by a machine and produce the desired output.

Touch Screen

A touch screen is a computer screen that often serves as an input device. A user communicates with the device by pressing pictures or words on the screen, which are responsive to pressure.

When you touch your phone, an electric circuit is completed at the point where your finger makes contact, and the electrical charge at that position is changed.

A touchscreen is a system that combines an input (‘touch panel’) and output (‘display’) device.

Instead of using a mouse, touchpad, or other such items, the touchscreen allows the user to communicate directly with what is displayed.

Optical Character Reader (OCR)

OCR is an input device (or scanner) that can read a printed text, special characters (such as alphanumeric keys and numeric characters) printed paper, and feed it to the pc data. it’s used as a lightweight source to read characters printed on paper.

OCR scans the text optically, character by character, converts them into a machine-readable code, and stores the text on the system memory.


Bar Code Readers

Bar Code Reader is one sort of data input device used for reading bar-coded data (data within the sort of light and dark lines). Barcoded data is usually utilized in labeling goods, numbering the books, etc.

Bar Code Reader is a handheld scanner, which scans a Universal Product Code image, converts it into an alphanumeric value, which is then fed to the PC for further use.

Optical Mark Reader (OMR)

OMR may be a special sort of optical scanner device used to read pencil marks on multiple choice question answer sheets or other documents in a similar form. It is specially used for checking the solution sheets of examinations having multiple-choice questions.

Tests and surveys completed on these forms are read in by the scanner, checked, and the result is saved to a file.

Digital Camera

A digital camera is a sort of data input device that takes pictures. It’s utilized in film industries, TV, photo snap, making marriage video, etc.

Once taken a photograph, it is transformed into a computing system in a digital way and manipulated by the graphics program and hence, produces a printed picture.

by Tech andro

Leave a Comment