When does a "ball" occur? baseball

A base on balls (BB), also known as a walk, occurs in baseball when a batter receives four pitches that the umpire calls balls, and is in turn awarded first base without the possibility of being called out.

A ball occurs when the pitcher throws a pitch outside the strike zone and the batter does not swing at it.

Here were two answers that I found just in case the other one was not correct.

Hope that this was helpful!