The UEFA Champions League, which evolved from the European Champion Clubs' Cup, is a seasonal club football competition organized by UEFA since 1992 (or overall in its older format since 1955) for the most successful football clubs in Europe. The prize, the European Champion Clubs' Cup (more commonly known as the European Cup), is the most prestigious club trophy in the sport. The UEFA Champions League is separate from the UEFA Cup.
The tournament consists of several stages. In the present format it begins in mid-July with three preliminary knockout qualifying rounds. The 16 surviving teams join 16 seeded teams in a group stage. Eight group winners and eight runners-up enter the final knockout rounds, which end with the final match in May. Previously only the champions of their respective national league could participate in the competition; however, this was changed in 1997 to allow the runners-up of the stronger leagues to compete as well.