The parts of a computer

Step 1 Warm-up recall

From Module 6: what is an interface?

Your answer

Private: nothing you type here is sent or stored.

Step 2 Learning goal

By the end of this lesson you can:

• name the main parts (Foundation);
• state the job of each (Core);
• say which parts keep data without power (Core).

Step 3 A familiar example

A kitchen has a cook, a worktop, a pantry and a hatch. The cook works on the worktop, the pantry keeps ingredients, and the hatch brings orders in and food out.

Step 4 Clear explanation

A computer is a machine that takes input, processes it by following stored instructions and gives output. Its main parts work together as in the figure.

The processor (central processing unit or CPU) does the work. The memory (random access memory or RAM) holds what the processor is using now, and it is lost when the power goes off. Storage keeps files for the long term. In the kitchen picture, the cook is the processor, the worktop is memory and the pantry is storage. When you open a document, a copy moves from storage to memory, and unsaved changes in memory are lost if the power fails. The entry on the computer places these parts in their history.

Step 5 Worked example (4 marks)

A document is open and the power fails before saving. Why is the latest typing lost?

1. While open, the document is held in memory. (1 mark)
2. Memory loses its contents when power goes off. (1 mark)
3. Only the last saved copy is in storage. (1 mark)
4. Answer: unsaved changes were only in memory. (1 mark)

Step 6 Learner practice (instant-marked)

Step 7 Recap

• Processor, memory, storage and devices work together.
• Memory is temporary; storage is long term.
• Unsaved work lives only in memory.

Step 8 Exit ticket (ungraded)

Name the part that holds the program being run right now.

Your answer

Private: nothing you type here is sent or stored.

Step 9 Go further (Extension)

Read the entry on the computer and list the parts it names.