Zipper: most people know what this is... a fastener of a strip of teeth that connect with each other.
Here are the different types:
Front Side of Invisible Zipper
Back Side of Invisible Zipper
Invisible zipper: Plastic. Usually teeth set behind so they are hidden when sewn into a garment. Usually need a specific presser foot for this. Used in skirts, dresses and some pants.
Separating zipper: Plastic or metal. One way or two way. Stopper at bottom of zipper makes it possible to disconnect tab and teeth completely. A two way zipper has two tabs. Used in jackets and shirts.