Poker is a card game in which players wager money on the outcome of a hand based on probability, psychology and game theory. The game has many variations and is played by millions of people around the world. It became popular in the early 21st century as the advent of internet poker and television broadcasts of major poker tournaments turned it into a spectator sport.

Depending on the rules of the game, one or more players are required to place an initial amount of money into the pot before cards are dealt. This is called a forced bet and comes in the form of an ante or blind bet. The dealer then shuffles the cards and deals each player two cards face down. The player on their left then cuts the deck and the first of what may be several betting rounds begins.

Each round, the players will either “call” a bet by placing their chips into the pot or they can “raise” by adding more chips to the pot. If a player wishes to stay in the pot without raising, they can “check.”

As the game progresses, the players will usually reveal their hands and the highest ranked hand wins the pot and all bets. Some games allow players to replace the cards in their hand with new ones, which is known as a “replacement” or “re-draw.” Other rules vary from game to game such as how a pair is made (two matching cards of one rank and three unmatched cards of another) or how a flush is made (3 cards of consecutive rank but of different suits). Players can also bet on bluffing, pretending that they have a high-ranked hand when they do not.