A triple in baseball occurs when a batter reaches third base on one hit. This is similar to a double, in which a batter reaches second base in a single hit. A triple is rarer than a double, but not as rare as a home run, in which a batter reaches the home plate in a single hit.
A triple occurs when the batter has enough time to reach third base. This can be achieved by using a strong swing, such as a line drive, to make the ball harder to catch, or if the reflexes of the defense team aren’t fast enough to put the batter out before they reach third base.