What privileges can you unlock with points?

I don't think I've actually seen the answer to this anywhere yet, I just know you have to be a member for a certain amount of...

I tried answering a question on here but it wouldn't let me because I didn't have any points.

How are some users so high on the leaderboard?

because I noticed on a couple things on mine people had taken points away?

Everyone keeps mentioning they will give someone 5 points if they get there answer right, how do you do that?

Does it depend on the subject or does everyone get the same amount of points for every How To they do?

or when you like it does it do it automatically?

need help understanding if I can make points for answering questions?

Like sometime it says "you will get 2 points if someone like your answer" & other times it will say "7 points"...

Who's the one or ones who are losing money when we gain it? Also, are the admins alloud to cash out their points?