AHAs are water-soluble acids and help peel the surface of the skin to remove dead skin cells and reveal new, more even-toned skin. Products with AHAs work as exfoliants to gently help you get smoother skin and with time, get rid of dark spots within the skin. 

BHAs, on the other hand are oil-soluble acids, and go deep within the skin to rid excess skin, oils and impurities. Salicylic acid, a commonly found BHA, is great to address acne concerns as well as overly oily skin.