The common answer will be the engine and the wing, Yes but does the engine or the wing alone make an airplane to attain flight? NO.
The basic principle influencing the flight of an airplane is Newton’s third law of motion,
"For every action there is an equal and opposite reaction."
The further explanation is continued below.
An aircraft requires two things: thrust and lift
Thrust is the forward motion provided by a propeller or jet engine, while an aircraft is moving in higher speeds the pressure variation on an aircraft wing will create a low pressure (high-wind speed) on the upper surface and high pressure (low-wind speed) on the lower surface which helps the aircraft to lift itself from the ground surface.
In an aircraft, four different forces act on it. They are lift, drag, thrust weight.
Thrust force is created by the propeller or jet engine of an aircraft. Thrust makes the aircraft to move forward.
The lift force as mentioned above is created by the aircraft wings. While aircraft moves in a forward direction a pressure variation is created in the aircraft wing which in turn produces lift.
Drag force is created by the structure of an aircraft. Drag force is the opposing force acting on the aircraft while moving in the forward direction. Aerodynamic frontal structure of the aircraft, wing and tail helps in reducing the drag produced.
Weight as the word denotes is the total weight of an aircraft. This force is proportional to the gravitational force. The Center of gravity plays a vital role in reducing this force.
These are the four forces acting on aircraft. Balancing these forces gives a perfect flight to an aircraft.