Refer to figure.
Paralleling generators is when two generators supply one bus bar. This allows the load to be shared between the two generators and has the added advantage of maintaining power on the busbar in the event of one of the generators failing. Both real and reactive loads must be matched to ensure correct load sharing between AC generators operating in parallel. When they are connected in parallel, the reactive loads are balanced by regulating the energizing current (exciter field current). On the other side, real load sharing is achieved by increasing the torque input to the lower speed alternator and vice versa.

Real Loads – actual working load directly related to the mechanical power (torque) supplied to the alternator (the engine or the CSDU). It is called “real” because it is dependent on the torque at its output shaft available for supplying aircraft’s electrical equipment.
Reactive Loads – vector sum of inductive and capacitive currents and voltages (in KVAR).