Being one of the largest passenger aircraft in the world it is not so difficult to recognize the Airbus A380. The easiest recognition point is obviously the double passenger deck over the full length of the fuselage. The Boeing 747 also has a double deck but only along a part of the fuselage. For the rest the Airbus A380 has a very conventional appearance with low mounted wings, engines under the wings and a regular tail. The only odd thing is the location of the cockpit: its windows are placed relatively low as the cockpit is located on the lower deck.
There is essentially one version of the A380, the A380-800. It is available with Rolls-Royce Trent 900 (A380-841/-842) or Engine Alliance GP7000 (A380-861) turbofan engines.
The A380plus was to be an improved version of the A380-800, with split-scimitar winglets and other wing improvements. The modifications were also available as a retrofit for existing aircraft. So far, the modification has not been done to more aircraft than the prototype.
Confusion possible with
The Airbus A380 and Boeing 747 have in common a two-deck fuselage, but the A380 has it over the full length and the 747 clearly only partially. Also, the Boeing 747 has the cockpit on the upper deck. Therefore it is unlikely to confuse them.