The answer to 'supply line vs' is that supply lines and pipes serve different purposes in a plumbing system. Supply lines are flexible, small-diameter tubes that connect fixtures like sinks, toilets, and appliances to the main water pipes. Pipes, on the other hand, are the larger, rigid components that make up the main water distribution system in a home.
Supply lines are typically made of materials like braided stainless steel, copper, or plastic, and are designed to be easily installed and replaced. They are more susceptible to leaks and damage over time compared to pipes. Pipes are usually made of copper, PVC, or galvanized steel, and are the core components that carry water throughout the home. Pipes are more durable and long-lasting, but can be more challenging to install or replace.