Chapter 2 - Input and output devices

Keyboard

A device used for data entry into applications software and typing in commands to the computer.

USB

A method of connecting a keyboard to a computer using a USB port.

Wireless

A method of connecting a keyboard to a computer without the need for physical cables.

Character Conversion

The process of converting a character pressed on the keyboard into a digital signal in the computer.

Touchscreen Technology

A method of using a keyboard on tablets and mobile phones by touching the screen.

Ergonomic Keyboards

Keyboards designed to provide more support to the wrists and hands to prevent Repetitive Strain Injury (RSI).

CPU

The central processing unit of a computer that determines which key has been pressed on the keyboard.

Index File

A file used by the CPU to identify which character the key press on the keyboard represents.

Numeric Keyboards

Keyboards used for entering numbers only, commonly used in automatic teller machines (ATMs) and point of sale terminals (POS).

Trackerball

A pointing device similar to a mouse, but with a ball on the top or side for controlling the pointer on the screen.

Remote Control

A device used for operating other devices using infrared signals, commonly used for televisions, DVD players, and Hi-Fi systems.

Joystick

An input device used for controlling a pointer on the screen, commonly used in video games and simulations.

Driving Wheel

An input device similar to a joystick, used for controlling steering movements in video games and simulators.

Touch Screens

An input device where the user can choose an option by touching a button or icon on the screen, commonly used in ATMs, mobile phones, and tablets.

Scanners

Devices used to enter information from hard copy into a computer, commonly used for scanning documents, photographs, and books.

Microphones

Devices used to convert sound waves into an electric current, commonly used for inputting speech and sounds into applications.

Sensors

Devices used to detect and measure physical quantities, such as temperature, pressure, light, sound, humidity, and pH.

Light Pens

Input devices that send signals to a computer whenever light changes are detected, commonly used for selecting objects on CRT screens and drawing with CAD packages.

Card Readers

Devices used to read information from cards, such as magnetic stripe readers for credit or debit cards, contactless debit card readers, and chip and PIN readers.

Radio Frequency Identification (RFID) Readers

Devices used to read information stored on RFID tags using radio waves, commonly used for tracking livestock, retail, and libraries.

Optical Mark Recognition/Reader (OMR)

Devices used to read marks or shading on forms, commonly used for reading questionnaires and multiple-choice examination papers.

Optical Character Recognition/Reader (OCR)

Devices used to convert text on hard copy documents into electronic form, commonly used for processing passports, converting documents, and number plate recognition.

Barcode Readers

Devices used to read information in the form of barcodes, commonly used in supermarkets and shops for product information and safety functions.

Quick Response (QR) Code Scanners

Devices used to read QR codes, which contain information such as business addresses, phone numbers, and website addresses, commonly used in advertising and augmented reality.

CRT Monitor

Least expensive type of monitor that uses an electron gun firing against a phosphor screen to create a picture made up of tiny dots colored red, green, or blue.

LCD Monitor

Made up of tiny liquid crystals that make up an array of pixels affected by changes in applied electric fields, requiring some form of backlighting to work.

LED Screen

Made up of tiny light emitting diodes (LEDs) that can produce a vast range of colors and are often used as backlighting for LCD screens.

Touch Screen

An input and output device used in smartphones, tablets, ATMs, ticket collection machines, and information kiosks that allows for faster entry of options and is user-friendly.

Multimedia Projector

Receives signals from a computer, television, or DVD player and magnifies and projects the image onto a large screen for presentations or home cinema systems.

Laser Printer

Produces high-quality hard copy output quickly and relies on large buffer memories to store data before printing.

Inkjet Printer

Used to produce good-quality hard copies, especially for low-output volumes and photo-quality printouts.

Dot Matrix Printer

An impact printer that presses a print head against an inked ribbon to produce slow, noisy, and lower quality output compared to inkjet and laser printers.

Graph Plotter

Uses a pen, pencil, or marker pen to draw multiple continuous lines and is commonly used for architecture and engineering drawings.

3D Printer

Used in computer-aided design (CAD) to build solid objects layer by layer using materials such as powdered resin, metal, paper, or ceramic.

Speakers

Output devices that produce sound and are used in phones, computers, multimedia presentations, and for visually impaired individuals.

Actuators

Mechanical or electromechanical devices, such as relays, solenoids, or motors, used to control physical devices like motors, pumps, switches, and buzzers.