Poker is a card game that involves betting and the formation of hands. The goal is to win the pot at the end of each betting round by forming a high-ranking hand. Players can make their hand by combining cards of a certain rank, or they may choose to bet on the chance that they will improve it with further draws. The dealer wins the pot if nobody has a better hand, or if everyone busts.
After each player receives their 2 hole cards, the first of several rounds of betting begins. This is usually initiated by 2 mandatory bets called blind bets placed into the pot by the players sitting to their left. These bets are essentially forced and provide an incentive for players to play the game, but the rest of the money that is put into the pot is done so voluntarily by the players who believe that their action has a positive expected value or who want to bluff other players for various strategic reasons.
When a player decides to place a bet, they can either call, raise, or fold. Folding surrenders the hand to the next player, while calling means that a player will place a bet equal to or higher than that made by the previous player. Raising is used to scare weaker players into folding, and it can also force players with drawing hands (that need additional cards to form a winning hand) to fold as well.