Position
Where you sit relative to the dealer button, which decides when you act. Acting last ("in position") means you see what everyone else does first; the button and cutoff are late position, the seats after the blinds are early position.
Frequently asked questions
What is position in poker?
Your place in the betting order. In position means acting after your opponent on each street; out of position means acting before them. The button is the best seat, the blinds the worst.
Why does position matter?
Because you see what they do before you decide. That lets you control the pot size, bluff more cheaply, take free cards and value bet more accurately — the same hand is simply worth more when played last.
How should position change your play?
Open far more hands from late position and far fewer from early. Positional advantage is why a hand like suited connectors is a clear raise on the button and a fold from the first seat, and why 'position over cards' is sound advice rather than a slogan.