Polyvinyl chloride
Vinyl polymers are the most common type of plastic. "Vinyl" is actually Ethylene, a gas that is used to make those plastics including PVC. In popular usage, "vinyl" is often short for PVC, but there are two other vinyl polymers which are more common. The most common is polyethylene, the second-most common is polypropylene. Another, less used, is polystyrene.