The short answer is that the UEFA Champions League is the club championship of Europe, and probably, therefore, the most prestigious football competition in the world other than the World Cup.
For a little background, it helps to understand how the world of football is organized. It’s all run by FIFA, an international crime syndicate that “governs” world football — sort of like how the Corleone Family sold olive oil. FIFA, much of whose leadership is under indictment in the US, is divided into regions, and within each region there are three big competitions:
- A qualifying tournament to send some countries to the World Cup every four years.
- A nation vs. nation tournament for the regional championship; an example is the Copa America in South America.
- A tournament for clubs within that region, held each year.
What we all call the Champions League is the third of those for UEFA, the European region of FIFA.
A little reference for our US readers: The US is part of the FIFA region CONCACAF, which we won’t even try to translate because nobody else does. Within that, we have World Cup qualifying (a sore topic for Yanks at the moment), the Gold Cup tournament of nations every odd year, and the CONCACAF Champions League, which has been won by US teams exactly twice in 50+ years. Usually a Mexican team wins it.