Sports leagues are organized groups of teams or individuals that compete against each other in various sports. These leagues can be professional, where players are paid, or amateur, where participants play for fun or community pride. Examples include the National Football League (NFL) for American football and the English Premier League (EPL) for soccer. Leagues typically have a structured schedule, with teams playing a series of games throughout a season. At the end of the season, the best teams may compete in playoffs or championships to determine the overall winner. This competitive format helps to engage fans and promote the sport.