Input and Output Devices
Hardware · 4 question types
Exam Frequency Analysis
Past paper frequency (2018 to 2024)
This topic accounts for approximately 3% of your exam marks.
Typically tested as 'give one use of…' or 'describe how this sensor works' questions.
| Device | What it does | Typical uses |
|---|---|---|
| Keyboard | Lets the user enter text and commands by pressing labelled keys | Typing documents, data entry, software control |
| Mouse (optical / mechanical) | Tracks hand movement on a surface to move a cursor; left/right buttons let the user click and select | Pointing, clicking and selecting on a desktop interface |
| Microphone | Converts analogue sound waves in the air into a digital signal | Voice calls, voice recognition, recording, online meetings |
| Digital camera | Captures a 2D image (or a stream of images) as a digital file | Photography, video conferencing, webcams, smartphones |
| Barcode scanner | Reads the parallel-line pattern of a barcode and converts it to a number | Supermarkets, warehouses, libraries |
| QR code scanner | Reads the 2D dot pattern of a QR code and converts it to text or a URL | Smartphone apps, marketing, contactless menus |
| 2D scanner | Captures a flat 2D image of a document or photo | Digitising paperwork, archiving, photo editing |
| 3D scanner | Captures the 3D shape and dimensions of an object | Reverse engineering, design, medical imaging, custom prosthetics |
| Touch screen | Combines a display with a touch-sensitive overlay, allowing the user to point and tap on the screen itself | Smartphones, tablets, ATMs, kiosks, modern monitors |
| Sensor | Measures a physical property (light, temperature, motion, etc.) and converts it to a digital reading | Monitoring and control systems (see section 5) |
A useful test for "input vs output": ask whether information is going into the computer (input) or out of the computer (output). A touch screen is both: the touch part is input, the display part is output.
Identifying built-in input devices for a specific device
What comes up: a question describes a device (smartphone, smartwatch, mobile phone) and asks you to name two input devices it contains.
Write: any two from: touchscreen, microphone, digital camera, sensor (name a specific type, such as accelerometer), button or keypad/keyboard (where applicable). The mark scheme accepts all of these; give any two that fit the device described.
Watch out: a sensor counts as an input device (it sends data into the computer). Do not list the screen or speaker — those are output devices and will score zero.