Poker is a card game in which players wager chips (representing money) on the outcome of a hand. The highest-ranking hand wins the pot. There are many different variants of poker, but they all share certain features.

A standard pack of 52 cards forms the basis for most games; some also include jokers or other wild cards. The cards are ranked from high to low (Ace, King, Queen, Jack) and there are four suits (spades, hearts, diamonds, and clubs).

Each round of poker has one or more betting intervals. The first player to act has the privilege or obligation to make a bet, and each player in turn must either call the amount of the bet made by the player before them, or raise it. If a player chooses not to call, they may “drop” their cards and forfeit that round.

When a player is not sure whether they have a good hand, they can bet heavily to try to convince other players that they are holding a great hand. This is called bluffing, and it can be effective if done correctly.

To be a good bluffer, you need to understand your opponents. Look at their eye movements, idiosyncrasies, betting patterns and other tells. You also need to learn to read them; if they tend to fold early on, for example, they are often easy to bluff into calling. Aggressive players, on the other hand, can be more difficult to read because they will often raise their bets before seeing their cards.