The term All-In is when a player commits all of his or her chips to the pot. It is one of the most common phrases used at the poker table, and is a verbally binding phrase in most poker casinos.
If you say “I’m all-in” there is no further action you can take, and all of the chips in front of you are committed to the pot.
Example: John bets and you decide to raise him for the remainder of your chips. You say “All-in,” instantly committing your stack, and the action is on John to call or fold.« View All Poker Terms