Every website Daniel visits has the same popup. "This website uses cookies." Accept. Decline. Manage settings.

He's been clicking through it his whole life without knowing what it means.

So he asked his mom.

A browser cookie isn't food. It's a tiny text file that a website saves on your device when you visit. Its original job was simple and useful — to give a website a way to recognize that the same browser has come back. Without cookies, every time you clicked to a new page on a website your shopping cart would empty. You'd be logged out every time you moved. The website would have no memory of you at all.

The name comes from a programmer named Lou Montulli, who in 1994 borrowed a concept from computer programming called a magic cookie — a small packet of data passed between programs to help them recognize each other. He  ...