How to mark a post as solved?

I’ve started a new thread and has now been solved.
How do I mark it as solved.
And by the way how does the person that helps the most, i.e., gives the most correct answers gets recognized (in the community at least). And I don’t mean cash.

I’ve just seen the answer to my second question on one of the sticky notes:
Rewarding Good Answers

Hi ruintc

On this board normal users can’t mark a thread solved, only moderators can do that, so if it’s noteworthy and should be marked solved, just contact a mod.

If you want to give recognition, use the star icon (add to this users rep) in the bottom left of any post by that user.