T-ball is a simple form of baseball made for very young children, usually about four to seven years old. The one big change is this: nobody pitches the ball. Instead the ball sits still on top of a rubber stand — a 'batting tee', which looks like a tall letter T — and the child swings at a ball that is not moving. That takes away the hardest part of baseball for a small child, which is hitting something thrown fast at you, so every child gets to hit, run, and feel good. Everything else is roughly baseball, but gentler: shorter games, softer balls, and in many leagues nobody keeps score. It is very much an American and Japanese/Taiwanese thing, tied to places where baseball is the children's game. You will also see it written 'tee-ball' or 'Tee Ball'. Grown-ups sometimes use it as a picture in ordinary talk: to say a question was 'a T-ball question' means it was made easy on purpose, sitting still and waiting to be hit.