What is main difference in ac motor and dc motor?

Also, there are differences in how you control their speed. I worked with motors in water waste sewage and AC motors were controlled with VFD " Variable Frequency Drive".

commutator is te difference between ac and dc motor.dc motors have commutator but ac motors don't have commutator.

DC motor gives high troque

AC motor has low maintainence

AC motor has better speed control

AC motor does not require commutator / brushes

AC = alternating current

DC = direct current

In direct current the electrons flow in one direction all the time, whereas with alternating current their direction of travel reverses periodically, perhaps 50 times per second.

If you supply DC to an AC motor it won't work, and vice versa.