The terms inverter, drive, and amplifier are used somewhat
interchangeably in industry. But there are subtle differences. A drive can
refer to the motor, the control electronics, or both. This term is used
particularly when the motor and electronics are integrated in the same housing.
The term variable speed drive can include many types of devices - anything that
has a variable speed output, which includes the GS series of inverters.

Amplifier more commonly refers to a linear amplifier for
servo motor control, or a stepper motor driver IC. Finally, we use inverter to
describe the GS Drive motor controllers because of the way the switching
electronics alternately inverts or directly couples its internal DC voltage bus
to generate a variable AC output. The terms AC drive, AFC (adjustable frequency
controller), AFD (adjustable frequency drive), ASD (adjustable speed drive),
and VFD (variable frequency drive) are also used to describe speed controllers
for three phase AC induction motors.