Computer Fundamentals

17 interactive videos. Watch each one, then try the idea live. Free, no account.

The Two-Symbol Trick

Why does a computer only know 0s and 1s — and how is that enough for everything?

Click your favorite game. Now follow the trip — disk → memory → CPU → GPU → screen, 60 times a second.

Peek inside a photo. A song. A document. Same idea — different bytes.

Functions: the one idea behind every computer program. A human picks the knob settings.

Functions are the parts. A program is what you get when you call them in the right order.

Every other program needs a manager. The operating system runs the show — Windows, macOS, Android, iOS.

The CPU thinks one thing at a time. The GPU does a million tiny things at once — that's how games and AI run.

Animation is just pictures shown fast. The game loop: read input, do the math, draw the next frame, 60 times a second.

Keyboards, cameras, microphones, screens, speakers. Numbers in — numbers out.

Watch a file get chopped into packets, flow across a connection, and get put back together.

How does a computer talk through air? WiFi turns 0s and 1s into invisible radio waves your router catches.

What is 'the internet', really? Billions of connections, routing packets around the globe.

The 'cloud' isn't really a cloud — it's somebody else's computer in a giant warehouse, ready 24/7 to answer your phone.

Type a URL, a big computer hands you some files, your phone draws them. Done.

Your browser fetches a few files from a server, then draws them as a page you can click. Magic? No — just a very fast read & render loop.

Google doesn't search the web when you type — it already read it. Crawlers, an index, and a ranking trick that decides what you see first.

How does video play instantly without downloading? Tiny chunks, smart guessing, and computers near you that already have the file.