Origins of the game
    Derived from English Billiards, the earliest form of Pool was called One Pocket, the first description of which dates back to 1775. A British form of the game appeared in 1869.    History    Etymology

Basic rules and objectives
    Pool, and all its variants, are played with balls on a rectangular table, usually covered in baize material. At the corners and the centre of the long sides are pockets into which the balls can drop. The players attempt to drop object balls into the pockets by striking a cue ball with the point of a stick ('cue'), causing the cue ball to collide with the object balls.
    Some games score points for pocketed balls, while others merely require the pocketing of a certain ball or balls, to determine a winner. Rules of the games throughout the world have become diverse, but standardised rules are now being accepted universally.

Clubs, societies, etc.
Billiard Congress of America
United States Pool Players Association
English Pool Association
International Professional Pool Players Association
Women's Professional Billiard Association