Tournament points

What does tournament points means to my rating or chess status?

When or where does they count or add to your account?

How important it is to have any, or does'nt it matters at all?

Do i get them when the rounds are finished or the whole tournament finished?

I do ask this because i played several tournaments and finished 3 times as no. #1.

Are those points all mine or do i have to share them with other players?

Is there somebody who will explain this to me?,, this is all new stuff for me..