The answer to 'what is supply line' is a pipe or hose that carries water or gas from the main source to a specific fixture or appliance in a home. Supply lines are typically made of copper, plastic, or stainless steel and connect the shut-off valve to the faucet, toilet, washing machine, or other plumbing fixture. They allow water or gas to flow from the home's main supply to the individual components that need it.
Supply lines are an essential part of a home's plumbing system, ensuring a reliable and consistent flow of water or gas to the various fixtures and appliances that rely on it. They must be properly installed and maintained to prevent leaks, clogs, or other issues that could disrupt the home's water or gas supply.