Poker is a card game in which players place bets on the rank of their hands and compete to win a pot (the sum of all bets placed during a hand). There are many different forms of poker, but most involve at least two players. Players must pay a fee to participate in each hand, called an ante, and are dealt five cards face down. Once betting begins, players may call a bet, raise it, or fold. If they fold, they forfeit the amount of money they have already deposited in the pot.
The highest poker hand is a royal flush, which consists of the five cards of the same suit in ascending order, such as A-K-Q-J-T. A straight flush beats a four of a kind in all cases except when there are wild cards in use, when the higher-ranking five of a kind wins (five aces beats five kings).
In addition to understanding the basic rules of poker, you should familiarize yourself with the betting system of your preferred game. You should also learn how to spot conservative players from aggressive ones, as this will help you determine the strength of their hands and make better decisions at the table. For example, a conservative player will typically fold early in a hand, while an aggressive player will often bet high on a strong holding and can be easily bluffed by weaker hands into folding.