The A-League is the top professional soccer league in Australia, established in 2004. It features teams from across the country, including major cities like Sydney, Melbourne, and Brisbane. The league operates on a promotion and relegation system, allowing for competitive play among clubs. The A-League season typically runs from October to May, culminating in the A-League Grand Final. Teams compete for the championship title, and the league also participates in international competitions, such as the AFC Champions League. The A-League has grown in popularity, contributing to the development of soccer in Australia.