The strike fighter/ground attack class of aircraft were first introduced in the Second World War, with fighters modified to carry out the ground attack role, supporting the troops from above. Today, these two classes can be distiguished by their design and primary role. The A-10, was mainly designed to fly slow, low and carry the most weapons possible to help the troops, therefore a ground attack aircraft. The modified F-15E, however, can fly fast, high, and designed to penetrate enemy defenses and take out key targets. Today, these aircrafts play a major role in air campagins.