You need to overcome your own weight--that is, the force of
gravity.
To overcome gravity, you need to create an upward force called
lift. That's what an airplane's wings are for.
To create lift, you need forward motion. That's what an
airplane's engines are for--they produce a force called thrust.
To keep moving, you need to overcome the resistance of the air--a
force called drag. An airplane's engines do that too.
