Software classification: input/output (I/O) devices

The idea

Within AQA 8525 software classification, input/output (I/O) devices are the hardware through which a computer receives data and sends results out. Input devices bring data in, for example a keyboard, mouse, microphone or sensor. Output devices present results, for example a monitor, printer, speaker or actuator. Some devices do both, such as a touchscreen. The operating system manages these devices, often using device drivers so software can communicate with the hardware without knowing its details. A multiple-choice question may ask which device is an input, which is an output, or which software component lets the OS control a device. Classify each option by the direction data flows.

What earns the marks

• Identifies input devices as hardware that sends data into the computer, such as a keyboard or sensor.
• Identifies output devices as hardware that presents results from the computer, such as a monitor or printer.
• Recognises devices that perform both input and output, such as a touchscreen.
• Links I/O device management to the operating system and device drivers.

Common mistakes and how to put them right

• Treating a touchscreen as output only.

  Put it right: Is that it both receives touch input and displays output.

• Classifying a printer as input.

  Put it right: Is that a printer sends results out, so it is an output device.

• Thinking device drivers are hardware.

  Put it right: Is that a driver is software letting the OS control the device.

Exam tips

• Decide the direction of data flow for each option before selecting an answer.
• Watch for 'both' devices and check whether the question allows a combined answer.
• Separate hardware (the device) from software (the driver) when the question asks which is which.