Poker is a card game in which players wager with chips. The highest hand wins the pot. The game may be played with one or more decks of cards, and has many variants. Most modern games are played with five cards, but the number of cards in the hand and the way the hands are evaluated differ from one game to another.
Each player begins the game by contributing to the pot (a sum of money) either a blind bet or an ante. This contribution is matched or increased by the next player in turn, unless they check, which means that they remain in the game without betting. In general, a player who matches or raises the previous bet is said to call.
The dealer then shuffles the cards and deals them to the players, one at a time. The cards may be dealt face up or down, depending on the game and the rules. After the deal, the first of several betting intervals commence.
You have a pair of kings off the deal. Brad discards three, Charley discards two, and Dennis raises a dime. He probably had a straight or flush. He also might have raised if he had a three of a kind. You can still beat him with your pair of kings, though.