A knockout tournament is a type of competition where participants are eliminated after losing a match. Each round consists of pairs of competitors facing off, and the winner advances to the next round while the loser is out of the tournament. This format continues until only one competitor remains, who is declared the champion. Knockout tournaments are commonly used in various sports, such as basketball, tennis, and soccer. They can also be found in games and contests, making them popular for their straightforward structure and excitement, as each match can determine a competitor's fate in the competition.