In baseball, an out occurs when the defensive, or fielding, team effects any of a number of different events, and the umpire rules a batter or baserunner out. When a player is called out, he is said to be retired. When three outs are recorded in an inning during a team's turn at offense, it is said that "the side is retired."
The most common ways batters or runners are put out are by strikeouts, fly outs, tag outs, and force outs, however there are many somewhat rarer ways an out can occur.
he fails to reach first base before a fielder with a live ball in his possession touches first base or tags the batter-runner (except when the batter is awarded first base, such as on a base on balls);