Videos
IGCSE Computer Science
Pick a topic to watch.
10 video lessons
21:16
Topic 1
Why Computers Use Binary
Inside a processor there are billions of tiny switches. Each one can only be on, or off. That is all a computer physically has — no threes, no sevens, no…
10:56
Topic 2
Data Transmission
You send a photo to a friend on the other side of the world. It does not travel as one lump. It is chopped into hundreds of small packets, each one labelled…
18:05
Topic 3
The CPU
The processor in your phone is doing something almost stupidly simple. Fetch one instruction. Work out what it means. Do it. Then fetch the next one. That is…
13:08
Topic 4
Hardware & Software
Here is a brand new computer. Every physical part works — the processor, the memory, the screen, the keyboard. Switch it on, and nothing happens. No desktop…
9:50
Topic 5
The Internet & the Web
You type a web address and press enter. Less than a second later, a page appears — a page that lives on a computer maybe ten thousand kilometres away. In that…
10:22
Topic 6
Automated Systems
Picture a greenhouse at three in the morning. Nobody is there. The air warms up a little, and a window slides open all by itself. An hour later it closes…
9:17
Topic 7
The Program Development Life Cycle
Every app on your phone was written by someone like this. But they did not start by typing code. Before the first line, the problem was studied, the solution…
13:16
Topic 8
Programming
Here is a short program. It reads five test marks and prints the total. The five marks are eight, nine, seven, six and ten, so the total should be forty. Watch…
8:17
Topic 9
Databases
Before computers, a library kept a drawer like this. One card per book, each holding the same few facts, all kept in order — so a librarian could find any book…
8:37
Topic 10
Boolean Logic
Look closely at this chip. There is nothing clever inside it. It cannot think. Inside are millions of tiny switches, and each switch can only be one of two…