Multiple choiceQuestion 1 · Recall
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By the end you can explain why a computer needs input, output, primary memory and secondary storage (including removable storage), and sort any device into the right group.
A processor on its own is a brain in a jar. It thinks incredibly fast, but it can't hear you, can't answer you, and forgets everything when the power goes.
Each of the other parts fixes one of those problems:
| Part | The problem it solves |
|---|---|
| Input devices | the processor can't get data from the outside world |
| Output devices | nobody can see, hear or use the results |
| Primary memory | the processor needs somewhere right next to it to hold the program and data it's working on |
| Secondary storage | everything in RAM vanishes when the power goes off |
Input device
A device that captures data or instructions from outside the computer (from a user or the environment) and converts them into a digital form the computer can process. Examples: keyboard, mouse, microphone, scanner, sensor.
Output device
A device that takes the results of processing and converts them into a form that is useful outside the computer: something people can see or hear, or a physical action. Examples: screen, printer, speakers, actuator.
Primary memory (main memory) is memory the processor can access directly: RAM and ROM.
Secondary storage keeps programs and data permanently. It is non-volatile, so files survive with the power off.
Think of a desk.
Where the picture breaks: ROM is also primary memory, but it isn't cleared at night. It's more like instructions printed on the desk itself.