To differentiate:
Football in the US of A is where you got these hulks all wrapped up in protective gear and mean looking helmets chasing an ellipsoid instead of a ball
Soccer is what the Japanase girls won the World Cup in.
In Europe, when the say fooball, they usually mean soccer, the stuff from the US is referred to as American Football.
There's also Aussie rules football ( kind of a blend of rugby and American football ), but that would only add to the confusion
