Football League One
In short
The third tier of the English football league system, sitting below the Premier League and the EFL Championship. It consists of 24 professional clubs competing for promotion.
In plain words
It is a professional football league in England. Teams play each other to try and move up to the Championship or avoid dropping down to League Two.
A simple example
A club like Bolton Wanderers or Wrexham might compete in this league to earn a spot in the higher divisions.
Why it matters
It provides a vital pathway for clubs to reach the top levels of English football. It also hosts many historic clubs with large fanbases.
Easy to mix up
Do not confuse it with the EFL Championship, which is the level directly above it.