When shopping for Topicals you are going to run across the words 
Salve and transdermal,
both very different compounds than your normal 
TOPICALS.
EX: Sunscreen, insect Repellents and antiseptics.

Your normal Topical compounds are made to remain on top of the skin surface 
Where a Transdermal Cream is going to deliver medicinal properties through the skin and into the Tissue, Joints and bloodstream.

When it comes to Salves our skin has a high concentrated amount of cannabinoid receptors 
when applying a Salve it activates the endocannabinoid system through those receptors