What is the difference between these flight modes: Manual, Stabilize, FBWA & FBWB?

Lorena -

Manual: Regular RC Control, no stabilization, All RC Inputs are passed through to the outputs. 

Stabilize: RC Control with simple stabilization, if you let go of the sticks then ArduPlane will level the plane. 

Fly By Wire A (FBWA): ArduPlane will hold the roll and pitch specified by the control sticks. 

Fly By Wire B (FBWB): ArduPlane is similar to FBWB but will try to hold altitude as well.