The answer to 'water line or water line' is that they are the same thing. A water line, also called a water supply line, is the pipe that carries fresh water from the main municipal water supply into your home. This pipe is responsible for delivering water to all the plumbing fixtures and appliances in your house. Water lines are typically made of copper, PEX, or PVC piping and run underground from the street to your home's foundation.
Water lines are an essential part of your home's plumbing system, providing the lifeblood of water that allows you to use sinks, showers, toilets, washing machines, and more. Properly maintaining and repairing your water line is crucial to ensure a reliable, consistent water supply and prevent costly water damage from leaks or breaks.