If you are outside the United States, FootBall means:
Two teams of eleven players each fight to get a spherical ball into the other team's goal.
The players are not allowed to touch the ball with their arms or shoulders.
Each team has a goal keeper that is allowed to touch the ball with his arms and shoulders when he is standing within the marked area around the home goal, which is called the PenaltyArea? (aka the "box").
A match lasts 90 minutes (two halves - 45 minutes each) plus 2-5 minutes of injury time.
In many countries (mainly in SouthAmerica? and EuropE) FootBall is not only a sport but also a way of life. Millions of people go to see the matches each weekend. This has a bad side, as groups of fanatics have often caused disturbances and sometimes tragedies (See HooliGans?).
The major event is the WorldCup? which is held every four years and in which 32 countries take part.
In the United States, the previous definition corresponds to SocceR.
However, if you are in the UnitedStates, FootBall is something different:
Two teams fight for control of an oval ball, which they have to carry in the arms and/or pass to another player on the same team, until the ball is stopped or the player carrying the ball get to the end of the field.
Here at Wikipedia, in the interests of peace among all the peoples of the Earth, we shall call this sport AmericanFootball
(Please someone that knows more about this that me, complete/correct it)