I have never come across the acronyms NPC and CIM for motors, but looking at some links, they look mainly as both being DC brushed types, so I suspect the name comes from the particular application, whatever that may be? Rather than the motor technology itself.
Max.
A bit more digging shows that the acronyms originate in the name of the companies that designed motors for portable applications and robotics.
CIM is Controlled Industrial Motor and NPC was originally National Power Chair.
Predominantly DC brushed.
Max.