In order to understand what "non-comedogenic" means, it may be helpful to break the word down. A comedo (or comedones, if more than one) is a type of pimple, or lesion that can form on your skin. Pimples differ according to their appearance and what causes them.
A comedo, the least severe form of acne, is the result of a clogged pore [source: American Academy of Dermatology]. Pores are the tiny openings in your skin that you can see when you look very closely, especially in a magnifying mirror. Inside those pores are hair follicles -- sacs beneath the skin that house the hair root -- and that's where pimples begin. When your body produces excess sebum, it can combine with dead skin cells and sometimes bacteria to plug up the pore. The result is a pimple -- a comedo. If the comedo is closed at the skin's surface, it's called a whitehead. When it's open at the skin's surface, and you can see the plugged follicle darkened by melanin buildup, it's called a blackhead [source: Mayo Clinic].
Non-comedogenic cleansers are typically oil-free. They break down the excess oils on your skin but don't strip your skin of the necessary moisture and nutrients it needs. They are also sometimes called non-acnegenic cleansers [source: Face & Skin Clinics].
One thing to keep in mind is that there aren't really any regulations specifying what a company has to do to call its cleansers "non-comedogenic," and products labeled that way may not work for everyone. Keep reading to find out what types of ingredients typically go into non-comedogenic cleansers so you can narrow down which one might work best for you.