Adheres to skin and hair

This ingredient helps stabilize emulsions and creates a light cream-gel texture, which isn't tacky to touch, but has very good adhesion to the hair and skin. It's a popular ingredient in sunscreens and anti-aging lotions.
Ammonium acryloyldimethyltaurate/beheneth-25 methacrylate crosspolymer is a copolymer of ammonium acryloyldimethyltaurate. A polymer is a large molecule made of repeating units (monomers).