Each poker hand is a culmination of various betting rounds, the number of which depends on the variation.
In Texas Hold’em there are four betting rounds, and each player must decide whether to fold, call, check, bet or raise when it is their turn to act, often basing their decision on the actions already taken by other players active in the hand.
Players check if they want to pass the action onto the next player but keep their cards. When a player checks, they don’t have to put anything into the pot unless they are playing with a big blind and/or small blind.
If you fold your hand in poker, you lay down your cards and stop playing the hand. Folding means you are out for that hand and relinquish your claim on the pot. Folding the cards involves tossing them to the dealer.
The player bets a certain amount based on the strength of his cards (or bluff if they are feeling adventurous). The bet must be more than the big blind.
Calling is what’s used to call a bet, which is when a player matches the amount that has been put in by another player in the form of a bet or a raise. If nobody calls the bet, the hand is over and the uncalled player wins the hand.
Raising is when a player increases the opening bet. After raising it, other players still active in the hand will have to either call, fold or re-raise, which is the act of increasing a raise that’s already been put in.
When all players have either folded or called the last raise, the betting round is over and all bets that were made are added to the pot. If all players except one have folded when a betting round concludes, the remaining active player wins.