Airbus is an airplane manufacturer and designer based in Toulouse, France. They manufacture many airplanes, and are famous for their family of jet airliners. They currently make the world's largest...
The difference between the A300 & the A340 is that: -The A300 has two engines, A340 has Four '4 engines 4 long hual' -The A300 is a short to medium range aircraft, while the A340 is a long range...
Quite abvious: the A380 is much bigger, weights almost three times the A300. Also, the A380 has four engines ins tead of two and has two decks instead of just on one for the A300.