A term used to describe the amount of money the player is restricted to buying in with in a poker game.
For example, in a $1/$2 live poker game, the maximum amount you can buy-in for is usually $200, or 100 big blinds.
Note: This is applicable to both poker tournaments and cash games.
A “tournament buy-in” includes the entry fee (which goes towards the prize pool) and the rake. For example, in a $10+$1 NLHE tournament, $10 goes to the prize pool and $1 goes to the online poker room.