Poker is a card game in which players place bets into the pot (representing money) and, in some cases, compete to have the best five-card poker hand. The game may be played by two or more people, and there are a number of different variants. The game is very popular in the United States and its play and jargon have become part of American culture.

When the cards are dealt a player must put in an initial contribution to the pot, called the ante. He can then decide whether to call a bet made by the player before him, raise it, or fold. In some games the initial player is obligated to make the first bet, and in others the decision is left up to each player.

A good poker player will study his opponents to determine how they react to certain circumstances. This helps him learn their betting patterns and read them better. For example, he can see if a player is conservative by seeing how often they fold early in the hand. Or he can see if a player has an aggressive style by observing how quickly they bet high.

Many poker players have tells, unconscious habits that reveal information about their hands. These can include eye contact, facial expressions, body language, or gestures. For example, a player might move his chips closer to the middle or glance intensely at other players. This behavior is considered bad etiquette and can give away information about his hand.