Football is a game played between two teams of 11 players each on a 100-yard field. The offense must gain 10 yards or more within 4 downs to earn a first down, or else turnover the ball. They can run or pass the ball and their goal is to score touchdowns worth 6 points or field goals worth 3 points. The defense aims to stop the offense from advancing and scoring. Special teams are also important for scoring or gaining better field position through kickoffs, punts, and returns. Football is played at many levels from schools and colleges to local leagues and professionally in the NFL and Canada.