H-Bridge freewheeling
The internal parasitic body diode of the MOSFET can be used, but will not be optimal since it's a byproduct of MOSFET construction (too slow, not soft recovery, inefficient). The body diode will be insufficient for some projects. A very few MOSFETs try to optimize the body diode a little bit to reduce overall component costs in a project, but >99% do not.

I always use external diodes.