Aviation refers to the activities related to flying or operating of an aircraft. It is the practical aspect or art of aeronautics, being the design, development, production, operation and use of aircraft. Aircraft includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, parachutes, as well as lighter-than-air craft such as balloons and airships.
Aviation has 2 main categories of flying : Civil aviation (representing all non-military aviation, both private and commercial.) and General aviation (includes all non-scheduled civil flying, both private and commercial e.g. business flights, air charter, private aviation, flight training, ballooning, parachuting, etc). Another category is the military aviation that concerns itself with building aircrafts to meet the capability requirements of military e.g. Bombers, Fighter jets, ground-attack aircraft, Unmanned Aerial Vehicles (UAVs), Missiles, etc.
vCalc's Aviation library contains equation and calculators applicable in activities surrounding flying or operation of an aircraft.