Typically there are two types:
1) Extended shaft versions e.g Lowara e-NSC & Ebara 3M, where the pump is attached directly to the drive shaft of a pump specific electric motor.
2) Close coupled versions e.g Ebara 3LS where the pump is attached to a standard IEC electric motor via a rigid coupling.
Extended shaft versions are a lower cost option and are more compact. Close coupled versions have the advantage of interchangeable motors which can be replaced without draining the pump or disconnecting the pipe work.