Here are some terms that you can find among the ingredients of your beauty products. They are acids that work for your skin in a positive way. Look for one or more of them, depending on your skin, it can have a great impact.
Hyaluronic Acid: for dehydrated skin
Salicylic Acid: cleanses & unclogs pores
Citric Acid: increases collagen production
Glycolic Acid: peels & exfoliates
Lactic Acid: softens & improves skin texture
L-ascorbic Acid: reduces dark spots & hyper-pigmentation
Retinoic Acid: reduces dullness & clears acne
Kojic Acid: brightens
Ferulic Acid: reduces signs of aging
Mandelic Acid: gentle exfoliator
Here you go. Not all acids are bad! Find the ones that work for your best interest.