What is a program? The recipe your computer follows

Press run below and watch the computer do exactly what each line says, in order, one at a time.

That list of steps is a program. The computer doesn't understand it; it just does each line, in order, incredibly fast.

Wikipedia: "A computer program is a sequence or set of instructions in a programming language for a computer to execute." The key words are sequence and execute: steps, done in order.

A computer is relentlessly literal. It does exactly what each line says, in the order they're written, and never guesses what you meant. Swap two lines and the result changes, because order is the whole point.

That's the opposite of how you talk to an AI, which does try to guess your intent. But here's the trick: when you vibe code, the AI turns your plain-English wish into exactly this kind of precise, ordered program. The code behind this very site was written that way.

So the machine underneath is still following literal steps. Your job when you vibe code isn't to write those steps by hand; it's to check they do what you actually meant, which is easier once you know that's all a program is.

Try it with the rules off. Run the program, then picture swapping two of its lines. The computer would follow the new order just as obediently, and get a different answer. That obedience is the whole idea.

Next in what a computer does: What is memory (RAM)?.