Like the latest top of the line performance supercar, an airplane is designed to be as efficient as possible in terms of aerodynamics. A flying aircraft is subjected to the same forces of gravity, wind direction, air and pressure.
The aerodynamics of airplanes design will focus on the kind and purpose of the aircraft. With that being said, all the airplane components stated above will be specifically designed according to the type of aircraft.
Commercial airplanes such as the Boeing 747 "jumbo jet" have large wingspans to generate modest amounts of lift. This is further complemented by the large engines to produce adequate amounts of power to produce lift. Since the Boeing 747 was designed to carry tons of passengers and cargo, the wings and the engine would have to be proportional to the amount of weight it was designed to carry. This will enable the aircraft to efficiently lift off the ground and cruise through the atmosphere.
Military jets such as the state-of-the-art F-22 Raptor have smaller wings (compared to a commercial aircraft) but are in proportion to the body or fuselage of the aircraft. You might notice that the Raptor has a different shape compared to conventional airplanes as this was primarily designed for stealth. The wings are a modified delta-wing design that were designed both to produce lift and enable the aircraft to travel at supersonic speeds (faster than the speed of sound.)
The engine or powerplant is also designed according to the capacity of the aircraft. An engine that is too large or powerful might affect the structural integrity of the aircraft. It may also affect fuel efficiency-thereby reducing the range of the aircraft.