Poker is a card game in which players place bets to win a pot. During the course of a hand, each player places bets that are either voluntary (based on expected value or other strategic considerations) or forced by the rules of the game. In the latter case, the amount placed in the pot is called a “pot size.”

A poker hand must contain five cards of consecutive rank to be considered a straight. A pair is two matching cards of the same rank; three of a kind is three cards of one rank and two unmatched cards of another; four of a kind is four cards of the same rank; and a flush is five cards in sequence, all of which are of the same suit. In addition, a royal flush is the highest possible hand, consisting of a pair of jacks, an ace, a queen, a king, and a ten.

The players’ hands develop over the course of several betting rounds. At the end of a round, all bets are collected into the central pot. In the process, players may replace or swap cards in their hand.

In a game of poker, it is important to understand how to read your opponent’s behavior and make adjustments accordingly. A good poker player learns to read their opponents by analyzing physical tells and studying how the players they play against act. They also learn to bluff occasionally to improve their odds of winning.