The main difference between PVC and copper plumbing lies in their materials and applications. PVC (polyvinyl chloride) is a lightweight, cost-effective plastic commonly used for drain, waste, and vent systems, due to its resistance to corrosion and ease of installation. In contrast, copper plumbing is a durable metal option favored for water supply lines because of its long lifespan and ability to withstand higher temperatures. While PVC is less expensive and easier to work with, copper offers superior longevity and antimicrobial properties. Ultimately, the choice between PVC and copper plumbing depends on the specific needs of a project, such as budget, location, and water quality considerations.