Professional leagues are organized competitions where teams or individuals compete in sports for monetary rewards and titles. These leagues are typically governed by specific rules and regulations, ensuring fair play and a structured format. Examples include the National Football League (NFL) for American football and the National Basketball Association (NBA) for basketball. Teams in professional leagues often consist of skilled athletes who have trained extensively in their respective sports. Fans support their favorite teams, contributing to the league's popularity and financial success through ticket sales, merchandise, and broadcasting rights. This creates a vibrant culture around professional sports.