Till now i have an experience with DC& brushless permanent magnet
motors in servo applications.
I'm looking for information about AC motors ,frequency inverter and
motion control system with such components.

Particularly im looking for answers for these questions:

1) When should I prefer using AC motor and when brushless motors?
2) What are the benefits of each system?
3) What are the differences between the AC motors types? ( induction,
universal, permanent magnet etc...) when should I use each one?
4) What is the difference between synchronous and un-synchronous
motor? Which suit for which application?

Thank you
Eli