Plastic windows what is it? And what is their advantage.

The very origin of the word plastic windows tells us about a lot, firstly about the fact that they are made of plastic, or rather from polyvinyl chloride (PVC). Of course, not everything is made of plastic, only the frame is made of plastic to it for stiffness. Metal is added, because PVC itself is not the most hard and the glass is traditional — glass (but not from organic glass).