Poker is a card game played by two or more players. The object of the game is to win the pot, which is the sum of all bets made during a deal. There are many variants of poker, but in all cases one player has the option to check (call without contributing to the pot) or raise his bet. During the betting round the cards are revealed and the highest ranked hand wins the pot.
The game is played with a standard 52-card deck, although some games use wild cards. The rank of a poker hand is determined by its odds (probability). If two or more hands are identical in rank then the pot is split evenly. A royal flush (A, K, Q, J, and 10 of the same suit) is the highest ranking hand. Other possible hands include four of a kind (four cards of the same number/picture); straight (five cards in a sequence but not all of the same suit); and a pair (two matching cards).
In most poker games the first player to act places a forced bet, usually an ante or blind bet. The dealer then shuffles the cards, the player on their right cuts, and then the dealer deals each player their cards, face up or down as appropriate for the variant being played. Each subsequent player then has the opportunity to bet. As the number of bets increases in a betting round the position of the player acting last becomes more important, as they have control over how much the pot size will be.