A ball is a round object that is used most often in sports and games. Balls are usually spherical but can be other shapes, such as ovoid (only in a few special cases). In most games using balls, the play of the game follows the state of the ball as it is hit, kicked, or thrown by players.
Balls were used in ancient times by the early Egyptians and the ancient Greeks and Romans.
Popular games involving balls include:
In baseball statistics
, a ball
is a pitch caught outside of the strike zone and not swung at by the batter. See ball (baseball statistics)
For the use of ball
, see ball (mathematics)
In modern times balls have been used in machinery. The ball bearing
is a device used to reduce the friction
of moving parts in a wide variety of machines. Ball bearings use hardened steel
For "Christmas ball," see Christmas tree