Cookie
A cookie is a tiny note that a website saves in your browser so it can remember you.
In a simple example
A shop uses a cookie to remember what is in your basket, or that you are signed in.
Why it matters to you
Cookies make sites easier to use, but some track what you do, so many places ask you to say yes first.
Do not confuse with
A browser cookie is not food, and it is not a virus. It is a small piece of saved text.