Poker is a card game played by two or more players. It is a game of chance that involves betting and strategic actions chosen by the player on the basis of probability, psychology and game theory. In most games there is an initial forced bet called an ante (amount varies by game, ours is a nickel). Once the cards are dealt the first of what may be several rounds of betting starts. At the end of the hand a player with the best poker hand wins the pot.
To get a good poker hand you must have at least two matching cards of one rank and two unmatched cards of another. The rest of the cards make up the community cards and you can combine these in any way you like to make your poker hand. A pair contains two cards of the same rank, a full house is three matching cards of one rank and two matching cards of another rank, a straight is 5 consecutive cards of one suit, and a flush is 5 cards of the same suit that skip around in rank.
After the first round of betting is complete the dealer deals three more cards face up on the table that anyone can use. This is called the flop. Say you have a pair of kings off the deal and you bet (put money into the pot) on it. Then the flop comes and you are holding an 8-8-7-5-4 of spades which is the nuts (the best poker hand possible at that moment).