The Airbus A300 is a 266 seat short/medium-range twin-engined aircraft that entered service in 1974. The Airbus A380 is a 853 seat long-range four engined aircraft that entered service in 2007.
Size and Number of Engines A300 is a 2-engine passenger/cargo jet. The A300-600 and the A310 is almost identical but has newer electronic cockpit and the fuselage is a little longer. The A340 is a...
well the most obvious difference is the size the A300 is a single deck twin engine and the A380 is a full length double decker 4 engined jet also the A380 is much more modern