Hydroxyl image from Wikipedia
As reported in What is salicylic acid?, salicylic acid is the beta hydroxy acid (BHA) used in many skin care products, and as shown in What is glycolic acid?, glycolic acid is an alpha-hydroxy acid (AHA) which is also used in numerous skin care products.
Salicylic acid is the only beta hydroxy acid found in cosmetic products, so when we discuss BHAs, the term beta hydroxy acid is interchangeable with salicylic acid.
While glycolic acid is is the smallest and best-known of the alpha-hydroxy acids, there are other AHAs which may be either naturally occurring or synthetic including lactic acid, citric acid, mandelic acid.
Full article at: What is the difference between alpha and beta hydroxy acids? Which product to choose | Skin Health Beauty