Baseball, in the simplest definition, is a game that consists of two teams that is played upon a baseball field. Each team alternates offensive and defensive play. A game normally consists of nine innings. An inning consists of one offensive period and one defensive period. Each offensive and defensive period consists of 3 outs. The offensive team scores a run when a member of the team successfully navigates around the bases. The offensive team reaches base by hitting the ball thrown by the defensive team. The defensive team can stop the offensive runner by touching the offensive player with the ball, touching the base before the offensive player reaches the base, or by catching the offensive player's hit in the air before the ball touches the ground. This is called an out. The team that has the most runs at the end of the game determines the winner of the game.
The game of baseball is a direct descendent of American 'Town Ball', a schoolyard game played in early America.