There are two categories of stropping, stropping on a clean substrate, and stropping on a substrate with compound.

Stropping is done to reduce the width of the edge, and to help remove and align any burrs along the edge.
# Clean Stropping
Stropping on a clean substrate achieves 4 things:
1. It realigns the edge
2. It burnishes the metal (moves it without destroying it), making the edge smoother
3. Abrasion - It makes scratches less defined and smooths out the blade
4. Removes coating - Some blades come with a manufacturer applied oil, you can use a strop to remove this coating

# Loaded Stropping
With a loaded strop, abrasive compound is applied to the strop to increase the rate of abrasion.