If I favour a question, does that mean I'm following it? And vice versa? What's the difference?
There isn't such a thing as "a followed question" in Stack Exchange interface, so the "favorite questions" serve this role. Marking a question as a favorite allows you to:
- Look it up later in your list of favorites (on your profile page), which can be sorted in various ways.
- Get a pseudo-notification of activity in those questions: it does not appear in your inbox, but is shown as a red badge with a number on the favorites tab in your profile.
- Search such questions in the future by using
See also: How do favorite questions work?