Machine-learning algorithms use statistics to find patterns in massive* amounts of data. And data, here, encompasses a lot of things—numbers, words, images, clicks, what have you.

To clear things up, I drew you this flowchart on the back of an envelope so you can work out whether something is using AI or not. This originally appeared in our AI newsletter The Algorithm.

They started small, with algorithms that sorted only 3, 4, or 5 numbers at a time, but these are important because they’re used by algorithms that sort longer lists.