BASICS.

Poker is a betting game for the purpose of winning a pool (or pot) formed by the money wagered. Poker is universally popular, not only for its suspenseful betting but also because it involves psychological ploys where strategy and money management are fundamental.

Each player begins with a stake, or amount of money. The object of the game is to arrange groups of cards together into sets commonly known as hands. At the beginning of each hand, each player typically places a small amount of money, known as the ante, into the center of the table (Some forms of poker use alternatives to antes such as blind bets, which are used in hold 'em.). At certain times during the deal and play of a hand, players may make additional bets, increasing the value of the pot. Whenever a player bets, other players must match the bet in order to continue playing. Players may also raise (increasing the amount of the bet) or fold (drop out of the hand, in which case they cannot win but will lose nothing more than what has previously been wagered).

The objective is to win the pot, which consists of the money bets made by various players during the hand.
One Player wins the pot in two ways:
He has the highest-ranking hand among the players who are still in the game at the end of the betting
or
All opponents surrender their claim to the hand (Fold).
The object of playing poker, however, isn't simply to win a lot of hands--it's to win as much money as possible. Over a series of many deals, successful players will be ones who maximize their winnings on the deals they win while minimizing their losses on the deals they don't win.

Poker is played with a 52-card deck with 4 suits composed of spades, hearts, diamonds and clubs. Cards are distributed clockwise.
The 4 suits are broken into ranks: the Ace is the highest ranking, followed by King, Queen, Jack, 10, 9, 8, 7, 6, 5, 4, 3, 2, Ace. The most versatile card in the deck is the Ace. Depending on the game, the Ace can be either the most valuable card of suit (worth more than the King) or the least important (worth less than the Two). The Joker does not have a suit and is not used in Poker.
Gameplay variations are so numerous that players often agree to "dealer's choice," in which the dealer gets to pick the variation each deal. The most common variation played is known as hold 'em, the same game that is played in many major poker tournaments. In most poker games, the top combination of five cards is the best hand. In spite of some forms of poker (such as Stud and Hold'em) are played with 7 cards, the best hand is composed of the best five card hand.
The best hand is a high hand in Seven-Card Stud and Texas Hold'em. In Lowball and Razz, the best hand is a low hand.
Maximum number of players (minimum 2 players):
10 Texas Hold'em
8 Stud poker
8 Razz poker

Most games require a token amount of money in order to receive cards (ante or blind bet), rotating around the table so that each player pays his fair share.

Any time a player at his hand can:
Check
Bet (If no one calls, the pot belongs to the player that bets)
Fold (No more money placed in the pot)
Call
Rise (If no one calls, the pot belongs to the player that rises)

The best hand wins the pot if 2 or more players still play the hand.