What Is Data?

You already know a lot about the world. You know that apples are red, that dogs bark, and that the sky is blue. But how did you learn all that? You noticed things! You saw, heard, and touched the world, and all those noticed things became information in your brain. Machines need to learn too — and today we find out how they get their information.

Data Is Recorded Information

Data is just information that has been written down or saved somewhere. When your teacher writes the temperature on the board every morning — 68°F, 72°F, 65°F — that list of numbers is data. When someone takes a photo of a birthday cake, that picture is data. When you type your name into a form, those letters are data. Data can be numbers, words, pictures, sounds, or almost anything else you can record and save.

Imagine you are a scientist keeping a nature journal. Every day you write down what birds you see and how many. Monday: 3 robins. Tuesday: 5 sparrows. Wednesday: 2 robins, 1 blue jay. That journal is full of data! Each entry tells you something about the birds in your yard. If you had a whole year of entries, you would start to notice patterns — like which birds visit most in spring. A machine does something very similar with its data.

Here is an easy way to remember it: if you can save it and look at it later, it is data. A daydream in your head is not data yet. But if you draw that daydream, the drawing becomes data!