Ball

A ball is a round object with various uses. It is usually spherical but can be ovoid. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling. Balls made from hard-wearing metal are used in engineering applications to provide very low friction bearings, known as ball bearings.

Although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus. The Spanish were the first Europeans to see bouncing rubber balls (albeit solid and not inflated) which were employed most notably in the Mesoamerican ballgame. Balls used in various sports in other parts of the world prior to Columbus were made from other materials such as animal bladders or skins, stuffed with various materials.

SuperBalls (originally "Super Ball") is an example of a bouncy ball invented by Norman Stingley, and manufactured by Wham-O in 1965. It is an extremely elastic ball made of Zectron, which contains the synthetic rubber polymer polybutadiene, vulcanized with sulfur at a temperature of 165 °C (329 °F) and at a pressure of 80 standard atmospheres (1,200 psi). The Super Ball has a very high coefficient of restitution. Dropped from shoulder level, a Super Ball will bounce nearly all the way back; thrown down, it can leap over a building. Bouncy balls are made from the elements silicon and sulfur. Lamar Hunt, founder of the American Football League, coined the term Super Bowl after watching his children playing with a Super Ball.

A football is a ball used to play one of the various sports known as football. In the distant past, crude balls such as inflated pigs' bladders were used, but balls are now designed by teams of engineers to exacting specifications. Older balls were usually stitched from 18 oblong non-waterproof leather panels, similar to the design of modern volleyballs and Gaelic footballs, and laced to allow access to the internal air bladder. This configuration is still common.