Button
1) This is a marker used in Hold'em poker to mark the dealer's position. This marker moves one seat to the left after each hand is complete. Since in Casino Hold'em games the dealer is an employee of the casino the marker is used to determine who must place the blind bets. See also Puck, Buck.
2) Small markers used in Roulette to identify the value of a player's chips temporarily.
3) Small marker used in Craps to identify the different types of wagers.