PWM Modules vs Channels
That particular PIC has two "simple" CCP modules (that can be configured for basic PWM) and a single "power control" PWM module that can be configured to provide up to four, differential, PWM outputs, each with different duty cycles, offsets, dead times, etc, but all synchronised to the same timebase.

You could drive two simple DC motors with the CCP modules; their PWM signals would not be guaranteed to be synchronised (which probably isn't a problem) and the PWM resolution would be 10 bits.  Driving a complex motor with the CCP modules would be difficult if not impossible.

You could drive up to four simple DC motors with the power control PWM module; their PWM signals could (if you chose) be perfectly synchronised and the PWM resolution would be 14 bits.  Alternatively, you could drive a more complex motor (BDCM or stepper, perhaps) with the power control PWM module.