Pool, also more formally known as pocket billiards (mostly in North America) or pool billiards (mostly in Europe and Australia), is the family of cue sports and games played on a pool table having six receptacles called pockets along the rails, into which balls are deposited as the main goal of play. An obsolete term for pool is six-pocket. There are hundreds of pool games. Some of the more well known include eight-ball (and the variant blackball), nine-ball (with variants ten-ball and seven-ball), straight pool (14.1 continuous), one-pocket, and bank pool. There are also hybrid games combining aspects of both pool and carom billiards, such as American four-ball billiards, cowboy pool, and bottle pool.