Both competitions have viewed structure variations, with expansions in the amount of collaborating teams, introduction of new rounds, and adjustments in qualification conditions over time. The group stage was performed from September to December, whilst the knockout stage began in February, with matches normally performed on Tuesday and Wednesday evenings. https://keo-nha-cai-tv53197.wssblogs.com/36314649/the-best-side-of-what-are-the-uefa-champions-league-and-uefa-europa-league