VPIP stands for Voluntarily Put In Pot. It is a statistic used in poker to track how often a player is putting money into the pot preflop. It is the percentage of hands in which a player voluntarily puts money in the pot preflop i.e., makes a call, raise or 3-bet, out of all the hands they are dealt.

VPIP is typically used as a key indicator of a player's overall aggressiveness and how loose or tight they are playing. For example, a player with a high VPIP (e.g., 30% or more) is generally considered to be playing a wide range of hands, whereas a player with a low VPIP (e.g., 10% or less) is playing a much tighter range of hands.

VPIP is commonly used in conjunction with other poker statistics, such as PFR (Pre-Flop Raise), which measures how often a player raises preflop. 

These statistics can help give a more complete picture of a player's playing style and tendencies.