What it is
Cookies are small pieces of data a site asks your browser to store and hand back on later requests. They hold session state, preferences, and very often tracking identifiers.
Why it matters
What a site sets before you have interacted with it says a lot. Session cookies show how logins are managed, and third-party cookies name the analytics and advertising companies involved. The flags on each one, Secure, HttpOnly and SameSite, show how carefully the site handles them.