The UEFA Champions League is the annual tournament to decide Europe's top club across all domestic leagues.
It started as the European Cup in 1955, then was rebranded "UEFA Champions League" in 1992.
The European Cup was inspired by tournaments like the Football World Championship and Mitropa Cup.
Teams that don’t quite make the cut for the Champions League compete in UEFA’s second-tier tournament called the Europa League.
The competition begins with 79 teams, and then moves to 32 teams in the group stage.
26 top-performing teams qualify for the group stage in advance, while the remaining 53 teams fight for the last 6 spots.
In the group stage, 32 teams are drawn into 8 groups and play each other in a double round-robin system.
The 16 surviving teams proceed to the knockout phase, in which the winners of the group stage play the runners-up from other groups.
The tournament uses the away goals rule, meaning the team that scores the most ‘away’ goals over two games has the tiebreaker.
The quarterfinals and semifinals are played in a two-legged format, and the tournament comes to a close with one final match.
The tournament awards money to all the teams based on two factors: progress through the tournament and the value of TV rights in the club’s home nation.
The winner also advances to the FIFA Club World Cup, plays in the UEFA Super Cup, and gains entrance to the next year’s Champions League.
