at the top is the single division of the premier league (level 1). this is often called the "top-flight". it has 20 clubs. they were all located in england until the 2010–11 season. however, two welsh teams (swansea city and cardiff city) have since played in the league. below the premier league is the english football league (efl). this used to be the football league. it has three divisions of 24 clubs each: the championship (level 2), league one (level 3) and league two (level 4). the 20 clubs in the premier league and the 72 clubs in the english football league are all full-time (all the time) professional clubs. the premier league teams are still often called 'league' clubs. this is because before 1992 the football league, as it was called then, included all 92 clubs in four divisions. in 1992, the premier league started, and became separate. clubs outside this group of 92 teams are called 'non-league' clubs (i.e. non-efl). however, they also play their football in league competitions.