elitkh wrote:

what is the different betwean AC brushless motor and DC brushless
motor?

"DC brushless"??? How can that be? Well, not your ordinary DC - more
of a hybrid DC / 3 phase. In short: a PM rotor and multi-phase stator.
An armature position sensor signals a controller to rotate the current
in the stator windings. More he
http://www.allegromicro.com/techpub2/hurst/bldcmot.pdf

see this link: http://www.hnmotor.com/main/productlist.aspx
this company produce 2 product lines:AC brushless and DC brushless.
does AC mean i should use inverter to oparate the motor?

I didn't look at their AC motors, but AC brushless is an induction
motor. Single phase cannot use an inverter (fixed speed). An inverter
can be used on 3 phase, but is not required. *Some* form of 3 phase
power is required. DC brushless always requires a controller, but not
your typical VFD.

HTH,
Bob