Billiard table
A billiard table, billiards table, or pool table is a bounded table on which billiards-type games (cue sports) are played. In the modern era, all billiards tables (whether for carom billiards, pool or snooker) provide a flat surface usually made of quarried slate, that is covered with cloth (usually of a tightly-woven worsted wool called baize), and surrounded by vulcanized rubber cushions, with the whole elevated above the floor. More specific terms are used for specific sports, such as snooker table and pool table, and different-sized billiard balls are used on these table types. An obsolete term is billiard board, used in the 16th and 17th centuries.
Cushions (also sometimes called "rail cushions", "cushion rubber", or rarely "bumpers") are located on the inner sides of a table's wooden rails. There are several different materials and design philosophies associated with cushion rubber. The cushions are made from an elastic material such as vulcanized (gum or synthetic) rubber. The chiefly American jargon "rails" more properly applies to the wooded outer segments of the table to which the cushions are affixed.
The purpose of the cushion rubber is to cause the billiard balls to rebound off the rubber while minimizing the loss of kinetic energy.
When installed properly the distance from the nose of the cushion to the covered slate surface is 1 7⁄16" while using a regulation 2 1⁄4" ball set.
...
Wikipedia