Each hardware component has one main job, and the computer behaves as it does because of how those jobs fit together. A good answer names the component, states its job, and follows the effect through to what the user sees.
This lesson finishes computing systems and logic. The logic side of hardware is in explaining selected logic circuits.
What does each component do?
Learn each component as a job and what happens when it is limited.
| Component | Job | If it is limited |
|---|---|---|
| Processor (CPU) | Fetches, decodes and executes instructions | Instructions take longer, so every task is slower |
| RAM | Holds running programs and data temporarily | Fewer programs fit, and the system slows or data moves to storage |
| Storage | Keeps files and programs when the power is off | Less room to save, and slow opening if storage is slow |
| Input devices | Bring data in, such as a keyboard or microphone | The computer cannot receive that kind of data |
| Output devices | Send results out, such as a screen or speaker | The result cannot be shown or heard |
The table gives you the outline of most answers. The middle column is the function and the last column is the behaviour.
Worked example: following one action
A student double-clicks a photo to open it. Here is the path through the hardware.
- The mouse, an input device, sends the click to the processor.
- The processor runs the instructions for the photo program.
- The photo file is read from storage, where it was saved.
- A copy is loaded into RAM, so the program can work on it quickly.
- The processor prepares the image, and the screen, an output device, displays it.
If the photo is very large and RAM is nearly full, step 4 takes longer, because other data must be moved out first. The student sees a delay before the picture appears.
The mistake: confusing RAM and storage
A common slip is to say RAM is where files are saved. The word “memory” sounds permanent, so students write it in answers about saving work.
| Question | Wrong answer | Right answer |
|---|---|---|
| Where is an unsaved document held while you type? | Storage | RAM, which is why unsaved work is lost if the power fails |
| Where is the saved file kept? | RAM | Storage, which keeps it with the power off |
| Why is opening a large file slow? | The file is deleted from storage | It must be copied from storage into RAM first |
The wrong answers name real components but give them the wrong job. Link each component to the behaviour in the question.
A sentence pattern for answers
Use this chain: “The [component] [does its job], so when [condition], the system [behaviour].”
For example: “RAM holds the programs that are running, so when many programs are open and RAM is full, the computer responds more slowly.”
Check yourself
A computer starts quickly but freezes when a video editor and a web browser are both open. Name the most likely limited component and explain the symptom in one sentence.
Answer
The most likely limited component is RAM. A quick start-up suggests the storage and processor cope with light work. Two heavy programs open together need a lot of RAM to hold their data.
A full answer: “RAM holds the running programs and their data, so when the video editor and browser together need more RAM than is installed, the system slows or freezes while it moves data to and from storage.”
A limited processor is also possible, because video editing is demanding. A good answer says which one it chooses and why.
What to study next
Test all four skills together in the computing systems and logic practice set. If a hardware question needs the logic layer, revisit reading Boolean expressions and truth tables.
If you want a teacher to help you build cause-and-effect answers, see online one-to-one Computer Science tuition.