In poker, "all-in" refers to a player betting all of their remaining chips. This means they cannot make any more bets or calls in the current hand, and if they win the pot, they will not be able to continue playing in the current game. Players typically go all-in when they have a strong hand, or when they are low on chips and want to try to win the pot to stay in the game. When one player goes all-in, any remaining players in the hand have the option to call the all-in bet, raise it, or fold. If multiple players are all-in in the same hand, a "side pot" is created for the players who have more chips than the player with the least amount of chips.