How computers work

Before you can understand how a computer learns, it helps to know how it works. Nine short lessons with pictures and things to play with, starting from a single on-or-off switch. No experience needed, and every lesson ends with a few questions to check yourself.

Your learning path

About 52 minutes in total

1Beginner5 min read

What is a computer, really?

A computer takes in information, changes it by following instructions, and gives back a result. Meet the idea behind every phone, game console and laptop.

2Beginner5 min read

Bits: why computers count in ones and zeros

Everything inside a computer is a tiny switch that is on or off. See how ones and zeros can count, and try it with a live binary counter.

3Beginner6 min read

Everything is numbers: text, pictures and sound

Letters, colours and music all become numbers inside a computer. Paint pixels and see the ones and zeros behind a picture.

4Beginner6 min read

Logic gates: how switches make decisions

AND, OR and NOT are tiny decision makers built from switches. Combine them and a computer can even add numbers.

5Beginner6 min read

Inside the machine: CPU, memory and storage

The processor, memory and storage each have a different job. See how they work together, using a kitchen as the picture.

6Beginner6 min read

Algorithms: step-by-step instructions

An algorithm is a clear list of steps that solves a problem. Learn sequence, choice and repetition, and a guessing trick that is always fast.

7Beginner7 min read

Programs: talking to a computer

A program is an algorithm written in a language a computer can follow. See variables, if, loops and functions, and why bugs happen.

8Beginner6 min read

Data: turning the world into a table of numbers

Rows, columns, features and labels: how information is arranged so that a computer can find patterns in it.

9Beginner5 min read

When rules run out: why computers need to learn

Some jobs are too messy to write rules for. See why, and how that leads to machine learning.

Then: machine learning

Ready for the next step.