What a computer does

Why this matters

A computer is a system that receives information, transforms it according to instructions, stores it and communicates results. The physical machine provides processing, memory, storage and input/output devices. The operating system coordinates those resources so programs do not all have to control the hardware directly.

Four roles to name

1. Processing performs instructions.
2. Working memory holds information needed now.
3. Storage keeps information for later.
4. Input/output moves information between the computer and people, devices or networks.

These roles can use different physical components, but the lesson is about purpose rather than shopping for parts.

The operating system

The operating system coordinates hardware, stored data and running work. It gives programs controlled ways to use memory, storage, the screen, keyboard and network interfaces.

Common mistake: the operating system is not every application on the computer. A browser uses operating-system services, but it remains a separate program.

Check your explanation

Point at one device you use and name one input, one output, one kind of working memory and one kind of storage. If you cannot verify a hardware detail, call it unknown rather than guessing.

Next stepFiles, folders and paths

See how the operating system gives stored data names and locations.