Stearic Acid is a saturated fatty acid, typically found in nature following palmitic acid--which is found in all animals, plants and microorganisms. The acid accompanies a myriad of animal and vegetable fats and oils, however it is more abundant in animal fat, with the exception of cocoa butter and shea butter.
As you may have guessed, this acid is a softening agent that is commonly used in the production of soaps, detergents and cosmetic products to include shampoos, body wash and shaving cream. While the soap available on consumer shelves is not made directly from stearic, it is indirectly included via saponification of triglycerides consisting of acid esters. These Esters, when combined with ethylene glycol, glycol stearate, and glycol distearate, are used to create a pearly effect in soap, body wash, shampoos, and other cosmetic products.
Stearic is also used in candle making, as well as an addition to simple sugar or corn syrup as a hardener for sugary candies.