Cookies

Short, because there is almost nothing to say.

Your session cookie, set when you sign in (including the demo vault). It keeps you signed in and is not used for anything else. If you open a password-protected published site, that site sets its own small cookie so it stays unlocked for you.
No cookies on these pages. Reading the marketing pages sets nothing.
No analytics cookies, no advertising, no third-party scripts on this site. We count page views on our own server by page and day, with no cookie and nothing about you. The light and dark switch on the Chief of Staff page keeps nothing after you leave.