Baseball leagues are organized groups of teams that compete in the sport of baseball. The most well-known league in the United States is Major League Baseball (MLB), which consists of two main divisions: the American League and the National League. Each league is further divided into several divisions, where teams play a regular season followed by playoffs to determine the league champion. In addition to professional leagues like MLB, there are also minor leagues, which serve as a developmental system for players. These leagues provide opportunities for young athletes to gain experience and improve their skills before potentially moving up to the major leagues. Other countries also have their own baseball leagues, such as the Nippon Professional Baseball (NPB) in Japan and the Korean Baseball Organization (KBO).