Being basketball player myself, here is how long a game is played. In elementary you have two 15 minutes half's. In high school it four 8 minutes quarters. In collage there is two 20 minutes half's. On the professional level a game has four 12 minutes quarters.
A professional basketball game is forty-eight minutes long. It is divided up into four quarters each 12 minutes long. A college basketball game is forty minutes long. It is divided into two 20 minutes halves.