Poker is a popular skill-based card game in which players with fully or partially concealed cards make wagers into a central pot. The pot is awarded to the player or players with the best combination of cards or to the player who makes an uncalled bet. Poker can also refer to video poker, a single-player game seen in casinos much like a slot machine, or to other games that use poker hand rankings.************************Poker is played in a multitude of variations, but most follow the same basic pattern of play. *********************** The right to deal each hand typically rotates among the players and is marked by a token called a 'dealer' button or buck. In a casino, a house dealer handles the cards for each hand, but a button (typically a white plastic disk) is rotated clockwise among the players to indicate a nominal dealer to determine the order of betting. ************************************* For each hand, one or more players are required to make forced bets to create an initial stake for which the players will contest. The dealer shuffles the cards, he cuts, and the appropriate number of cards are dealt to the players one at a time. Cards may be dealt either face-up or face-down, depending on the variant of poker being played. After the initial deal, the first of what may be several betting rounds begins. Between rounds, the players' hands develop in some way, often by being dealt additional cards or replacing cards previously dealt. At the end of each round, all bets are gathered into the central pot. ************************* At any time during a betting round, if a player makes a bet, opponents are required to fold, call or raise. If one player bets and no opponents choose to match the bet, the hand ends immediately, the bettor is awarded the pot, no cards are required to be shown, and the next hand begins. This possibility of winning a pot without showing a hand makes bluffing possible. Bluffing is a primary feature of poker, one that distinguishes it from other vying games and from other games that make use of poker hand rankings. *************************************** At the end of the last betting round, if more than one player remains, there is a showdown, in which the players reveal their previously hidden cards and evaluate their hands. The player with the best hand according to the poker variant being played wins the pot.*************************The most popular poker variants are as follows: Draw poker Players each receive five — as in five-card draw — or more cards, all of which are hidden. They can then replace one or more of these cards a certain number of times. Stud poker Players receive cards one at a time, some being displayed to other players at the table. The key difference between stud and 'draw' poker is that players are not allowed to discard or replace any cards. Community card poker Players combine individually dealt cards with a number of "community cards" dealt face up and shared by all players. Two or four individual cards may be dealt in the most popular variations, Texas hold 'em and Omaha hold 'em, respectively.