A football formation is a number set that describes the positions of players on the field. It determines how many players play on defense, the midfield, and the frontline. The first number always describes the defender, and so on. For example, a formation like 4-3-3 plays with four defenders, three midfielders, and three forwards.

Soccer formations describe the positions occupied by players in a team during play and are described in the form of the number of defenders followed by number of midfield players followed by number of attackers. For example, 4-3-3 would describe four defenders, three midfield players and three attackers.