Poker is a card game that involves chance, but also a significant amount of skill and psychology. It is played from a standard pack of 52 cards (with some variant games using multiple packs or adding jokers). A poker hand must contain five cards; the highest hand wins.
At the beginning of each hand, players are required to place forced bets into a pot in order to compete for the winning hand. These bets are typically called the ante or blind. Players may then either call, raise, or fold. If they raise, they add additional money into the pot in addition to their original bet. Regardless of the number of bets made, the player with the highest hand wins the pot.
During the first round of betting, Brad kept two cards, Charley kept one card, and Dennis discarded two cards (dealing replacements). This left you with the pair of kings, three spades, and a weak chance for a straight or flush.
You decide to call the raise, putting your money into the pot alongside the other players. This adds to the pot value, which means that if you have a good hand, you should bet into it. This forces weaker hands to fold and increases your chances of winning the pot. This strategy is called “riding out the danger zone.” This is a critical stage in the middle stages of a game. It is during this time that you need to tighten your range and focus on making strong hands rather than speculative ones.