There are 4 main types of Zippers, which are mainly differentiated by the material of the Zipper teeth: Metal Zipper: Mainly made of metal teeth, it can be brass, aluminum, stainless steel, etc. The most common metal zipper teeth is brass, which has high strength and good durability. The aluminum material is relatively light, but the slide smoothness is not as good as brass. The stainless steel material has less strength as brass; 
Plastic Zipper: also known as resin zipper, vislon zipper, its zipper teeth is POM(one kind of plastic). 
Nylon Zipper: also called as coil zipper, some customer all it "plastic zipper" as well, its zipper teeth is not real nylon, in stead, it is PET(one kind of plastic);other popular zippers like Invisible Zipper, Waterproof Zipper, Reflective Zipper, etc. is also made by Nylon Zipper with some changes. 
PVC zipper: it's one kind of Special Zipper, normally in transparent or half transparent color, material can be PVC, EVA, PE, etc.
