Algorithm

An algorithm is a recipe for getting something done: exact steps, in order, with no room for interpretation. A cake recipe, furniture assembly instructions, and directions to the bakery are all algorithms — for humans. Computer algorithms are the same idea, written strictly enough for a machine that never guesses.

What makes algorithms exciting is that some are dramatically better than others. Finding a number between 1 and a billion takes up to a billion checks the naive way — or about 30 by halving the range each time. That gap, cleverness beating raw speed, is the heart of computer science.