What is the difference between a stadium and a field?

Football is known in the USA as soccer. So both fields are the same. American's however refer to "American Football" when using the term "football". An American football field is 100 yards (approx 91m) with two 10 yard (approx 9.1m) end zones. End to end the fields are the same size.

Football is a sport played with the foot and a ball. Many other sports have also called themselves football.

Australian football, American football, Gaelic football, Rugby union football, rubgy league football.

However only one sport is officially called football and uses primarily the feet and a ball.

Australian rules football uses 4 goal-post, with the outer two worth 1 point and the inner, 7.