Poker is a card game that involves betting and the sharing of cards. It has a long and complex history, and many variants exist. It is traditionally played with a standard English pack of 52 cards, and some games use multiple packs or add wild cards (also called jokers).

In the simplest form of the game, each player puts in an amount of money into a pot before being dealt two cards. When it is their turn to act, they may choose to bet, raise or fold. A winner is declared when a player has a winning hand.

During the betting process, players can replace their own cards with new ones from those on the table or by drawing additional community cards. This can change the strength of a hand or allow bluffing. Depending on the rules of the game, some bets are compulsory, while others are optional.

A key skill in poker is being able to read other players, which means learning their tells, such as their eye movements, idiosyncrasies, hand gestures and betting behavior. For example, a player who calls frequently but then unexpectedly makes a large raise may be trying to signal that they have a strong hand.

Experienced players will often consider their opponent’s entire range of hands when deciding how to play their own. They will also try to estimate the probability of their opponents’ hands and the expected value of a bet. Over time, these concepts will become ingrained in the player’s brain and be applied automatically during the course of a hand.