What is the difference between "bookmarking" and "following" a question?

Question

In any question on StackExchange, there are two buttons that let you remember a question: the "Bookmark" button on the left of the pane (only available for questions) and the "follow" link below each post, which is available on both questions and answers.

What is the difference between those two buttons' functions, and when should I consider using each of them?

Answer 1

There's a proposed FAQ on Meta Stack Exchange precisely about this topic. @arghtype's answer summarizes the main differences.

when should I consider using each of them?

You should use the 'follow' feature when:

• you want to receive inbox notifications
• you want to keep the fact that you're following a post private
• you want to keep a reference to an answer, not to a question

You should use the 'bookmark' feature when

• you don't want to receive inbox notifications (but just keep the question as a reference); multiple comments/edits can get annoying
• you want an overview of all bookmarked question across the network in your network profile (the 'follow' feature only works on a per-site base)
• you want to help someone getting a Favorite Question badge

Answer 2

See The Follow Questions and Answers feature is now live across the Network .

To summarize:

1. Followed questions/answers will generate notifications in top bar similar to answers to your questions or upvotes.

2. Followed questions/answers are private to you.

3. Bookmarked questions are public and anyone can check which questions you bookmarked on your profile page.