Thanks, so far I've mainly stick to subscribing and using the bell for noticing new posts or threads there & I've also set preferences of (no) additional mails if new content getting shared, so you guess that "subscribing" describes news when notifications and "bookmarking" just as listing but no info which posts being new, just the titles summarized there?
Edit: just noticed it. So far I've just used that part for browsing through all posts/threads or finding interesting titles than reading the top line that refers to bookmark/subscribe.