It is not for nothing that this is called a family, because after several iterations (and names) this helicopter is still in production. The helicopter in question started its life as Sud Aviation (later Aérospatiale) SA330 Puma. The stretched variant was at first marketed as Aérospatiale AS332 Super Puma and AS532 Cougar, for the military version. Later Aérospatiale became part of Eurocopter, and the helicopters were renamed EC225 and EC725. Nowadays, the manufacturer is Airbus Helicopter, that markets the helicopters as H215, H225 and H225M. 

All versions more or less have the same basic appearance. A typical feature is the location of the two turboshaft engines, on top of the fuselage and in front of the main rotor axis. The air intakes are above the cockpit, the exhausts at the side of the gear box/engine hub. All variants have a high mounted tail rotor on the right side, with a single horizontal stabiliser on the opposite side. The retractable nose gear always has two wheels, while the main gear can have one or two wheels on each leg. The main gear is retracted in sponsons or small stubs, depending on the version.

To distinguish the different versions of the (Super) Puma & Cougar family you will have to look at

• the number of wheels on the main landing gear
• the number of main rotor blades
• the number of tail rotor blades
• the size of the sponsons
• the presence of a ventral fin
• the shape of the top of the vertical stabiliser
• the shape of the nose

Details will be added later.