Poker is a card game that involves betting and is played with cards and chips. The aim is to form a poker hand according to the rankings of the cards, and to win the pot (representing the money bet by all players) at the end of one or more betting intervals.
Each player is dealt a number of cards in rotation from a standard pack, or sometimes multiple packs, depending on the variant being played. The first player to make a bet is usually required to place an amount of chips in the pot equal or greater than that placed by the player before him.
The dealer shuffles the cards, then deals them to each player, starting with the player to his left, either face up or down, depending on the specific variant being played. The player to the right of the dealer may cut if they wish, and the dealer has last right to a full re-shuffle before dealing.
During a betting round each player has the opportunity to bet, check, raise or fold their cards. After all betting rounds have ended the dealer places a fifth card on the table that anyone can use (this is called the river). If one player has a higher ranked hand than any other they take the pot.
A big part of winning poker is observing your opponents and learning their tells. This can include subtle physical poker tells, such as scratching an ear or fiddling with a ring, but more often it involves noticing patterns in betting. For example, if someone calls every bet all night then you know they are playing strong hands and can be bluffed into folding their weaker ones.