Computers

Mainframe, server, personal computer, tablet or smart phone, embedded system.

A computer built inside another product to do one job — a washing machine, a card reader, a traffic light.

Nobody thinks of them as computers, so nobody asks who updates them, who can reach them, or what they record.

Roles, not machine types. The same computer can act as either.

Input, process, store, output.

Hardware is the physical parts. Software is the instructions telling them what to do.

Memory (RAM) holds what is in use and empties when power goes. Storage keeps things when it does.

A CPU does one complicated thing at a time, very fast. A GPU does thousands of simple calculations at once — which suits AI training.

Writing instructions in a language with a specific syntax so that a machine can carry them out.

Open: anyone may read, change and share the code. Closed: only the owner may — but there is someone accountable.

It moves a judgement from a person who could make an exception into a rule that cannot.

Who is able to check it? That turns a software question into a digital society answer.

Vacuum tubes (1940s), transistors (1950s), integrated circuits (1960s), microprocessors (1970s on), AI and cloud (now).

The switching technology inside — each one smaller, cheaper and more reliable than the last.

Components on a chip roughly doubled every two years. A prediction the industry organised around, not a law — and it has slowed.

Computing had been moving closer to people; the cloud moved the processing back into a data centre and left a screen in your hand.