Pixel
One tiny square of a picture, storing three numbers: how much red, green, and blue.
Zoom deep into any photo and the illusion breaks: it's a grid of tiny colored squares. Each square — each pixel — stores three numbers from 0 to 255: red, green, blue. Mix the three lights and you get every color a screen has ever shown you.
A 12-megapixel photo is 12 million pixels — 36 million little numbers. Filters, brightness, blur: all of it is arithmetic on those numbers.
The best way to make it stick: watch it run. Start an interactive lesson →