Football is a team sport that involves two teams of eleven players competing against each other. The positions in football are divided into offense, defense, and special teams. TAILBACK is an offensive position in football that is responsible for carrying the ball from the line of scrimmage. Halfback is another offensive position in football that is similar to TAILBACK but typically lines up behind the quarterback. BACK is an offensive position in football that is responsible for blocking and protecting the quarterback. Slotback is an offensive position in football that lines up between the wide receivers and the offensive line. STRIKER is an offensive position in football that is responsible for receiving passes from the quarterback. END is an offensive position in football that lines up on the outside of the offensive line. DEFENDER is a defensive position in football that is responsible for defending against the opposing team's offense. GUARD is an offensive position in football that lines up between the CENTER and the tackle. CENTER is an offensive position in football that is responsible for snapping the ball to the quarterback. SLOT is an offensive position in football that lines up between the wide receivers and the offensive line. LINEMAN is an offensive or defensive position in football that is responsible for blocking and protecting the quarterback. Fullback is an offensive position in football that is responsible for blocking and protecting the quarterback. Leftback is an offensive position in football that lines up on the left side of the offensive line. RECEIVER is an offensive position in football that is responsible for catching passes from the quarterback. Splitend is an offensive position in football that lines up on the outside of the offensive line. Tightend is an offensive position in football that lines up between the wide receivers and the offensive line. Lefttackle is an offensive position in football that lines up on the left side of the offensive line. Widereceiver is an offensive position in football that is responsible for catching passes from the quarterback.