What are the main types of aircraft?
The families that matter are set out in regulation, and they're divided by one thing: where the lift comes from.
The United States federal aviation regulations give the cleanest short definitions. An airplane means an engine-driven fixed-wing aircraft heavier than air, that is supported in flight by the dynamic reaction of the air against its wings. A rotorcraft, in the same section, is a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors. A glider is supported the same way an aeroplane is, but its free flight doesn't depend principally on an engine.
British law words the last one slightly differently. The Air Navigation Order 2016 defines a glider as a non-power-driven, heavier-than-air aircraft, deriving its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight, and then folds self-sustaining gliders and self-propelled hang-gliders in alongside it.
What a spotter sorts by
Not by those definitions, most of the time. Out at the fence the sorting is by job and by silhouette: the big fixed-wing jets carrying passengers, the light singles used for training and touring, the military types built around a mission, and the rotorcraft that trade speed for being able to land almost anywhere. Each family holds its shape, which is why a type can be named from a long way off.
The wings are different because the work is different, which comes straight out of how planes fly. Whatever the family, they all still need somewhere to land, and that's what a runway is. More on the sky.
Once you can tell the types apart, choosing the one to print gets easier, and gifts for plane lovers picks up from there. Plane gifts covers choosing when you cannot name the aircraft, and aviation gifts sorts the rest by recipient.
