Input and Output Devices

A physical component or device that is used to feed data and instructions to the computer

They allow users to interact with and provide data for the computer to process.

Function: Enters text, numbers, and commands How it works: Each key press sends a unique binary signal to the computer Uses: Writing documents, entering data Advantage: Simple and widely used Disadvantage: Can be slow for large data entry; prone to typing errors

Function: Controls pointer movement on a screen How it works: A small camera under the mouse detects changes in surface movement Uses: Navigation and control in user interfaces Advantage: Fast and accurate Disadvantage: Doesn’t work well on some shiny or transparent surfaces

Function: Converts sound waves into electrical signals. How it works: Sound vibrations are detected by a diaphragm and converted into digital audio data. Uses: Voice recognition, video calls, sound recording. Advantage: Enables voice input. Disadvantage: Can pick up background noise.

Function: Allows user to interact by touching the display. How it works: Resistive: Two layers touch when pressed, detecting position. Capacitive: Detects electrical current from finger touch. Infra-red: Uses light beams; touch breaks the beams. Uses: Smartphones, ATMs, kiosks. Advantage: Easy to use, no need for separate input devices. Disadvantage: Can get dirty; may need calibration.

Function: Reads barcodes (patterns of black and white lines) on products. How it works: Shines a laser on the barcode; the light reflected back is converted into digital data. Uses: Supermarket checkouts, inventory management. Advantage: Fast and accurate data entry. Disadvantage: Barcode can get damaged or smudged.

Resistive: Two layers touch when pressed, detecting position. Capacitive: Detects electrical current from finger touch. Infra-red: Uses light beams; touch breaks the beams.

Function: Reads QR codes (square barcodes with encoded data). How it works: Camera scans the code; software decodes the information. Uses: Payments, ticketing, marketing links. Advantage: Can store more data than a barcode. Disadvantage: Needs camera access and proper lighting.

Function: Captures still or moving images. How it works: Light enters through a lens, hits an image sensor (CCD or CMOS), and converts it into digital data. Uses: Photography, security systems, facial recognition. Advantage: Produces high-quality images quickly. Disadvantage: File sizes can be large; may need memory cards.

Function: Captures the image or shape of an object. How it works: 2D Scanner: Scans flat images (like documents). 3D Scanner: Scans the shape and depth of an object using lasers or sensors. Uses: 2D for document scanning; 3D for design, medical imaging, gaming. Advantage: Accurate reproduction of objects. Disadvantage: 3D scanners can be expensive.

hardware components that receive information from a computer system and present it to the user in an understandable form

They allow uses to see, hear, or physically experience the results of computer processing

Device that detects or measures physical properties and converts them into data for a computer

The collect data automatically from the environment without human input

Analogue data - temp, light, sound

It is converted into digital data and used to monitor or control systems - turning on lights, adjusting temp

Function: Converts electrical signals into physical movement. How it works: Receives signals from a computer and produces motion (e.g. by rotating, opening, or pushing). Uses: Automatic doors, robotics, temperature control systems. Advantage: Enables computers to control physical processes automatically. Disadvantage: Can wear out or malfunction mechanically.

Function: Projects digital images onto a large screen. How it works: Uses tiny mirrors and a spinning colour wheel to reflect light and form images on a screen. Uses: Classrooms, cinemas, presentations. Advantage: Produces bright, high-quality images. Disadvantage: Can be expensive; needs regular maintenance (e.g. bulb replacement).

Function: Prints text or images by spraying tiny droplets of ink onto paper. How it works: Print head moves across paper, releasing ink through nozzles. Uses: Home and small office printing. Advantage: High-quality color printing; relatively cheap. Disadvantage: Slow for large volumes; ink cartridges can be costly.

Function: Produces high-quality printed documents quickly. How it works: Uses a laser beam to form an image on a drum, which attracts toner powder and transfers it to paper. Uses: Offices, schools, business printing. Advantage: Fast and durable prints; good for high-volume work. Disadvantage: Expensive to buy; toner cartridges costly.

Function: Displays images using LEDs as light sources. How it works: Thousands of tiny LEDs light up individually to form images. Uses: Televisions, computer monitors, advertising boards. Advantage: Bright, energy-efficient, long-lasting. Disadvantage: More expensive than LCD; can suffer from “burn-in.”

Function: Projects images using liquid crystal display panels. How it works: Light passes through three LCD panels (red, green, blue), which combine to create full-color images. Uses: Classrooms, meetings, home theaters. Advantage: Good color accuracy and brightness. Disadvantage: Can have lower contrast than DLP projectors.

Function: Displays text, graphics, and videos. How it works: Uses liquid crystals that change alignment when an electric current passes through, controlling light from a backlight. Uses: Monitors, laptops, TVs. Advantage: Thin, light, low power usage. Disadvantage: Limited viewing angles; slower response time than LED.