I really love playing basketball, especially on a rectangular court. Basketball is my favorite limited-contact sport. 
I've never been a good player. I have to say out of all the sports, it is the most fun to watch even though I don't understand it.
Ever Since the game was invented in 1891 by Dr. James Naismith the rules have changed only slightly to make it more appealing. Its not hard at all. 
How many players on the court at one time per team. They move so fast I can never count.
There are only 10 players allowed on the court at any given time in a game. 
Sometimes I've noticed they get 3 points. How do they do that?
Its called a field goal , you can score three points for shooting from behind the three-point line, and two points if shot from in front of the line.