The answer to 'supply line or supply line' is that there is no difference between the terms 'supply line' and 'supply line'. They are used interchangeably to refer to the flexible hose that connects a plumbing fixture, such as a sink or toilet, to the main water supply line. Supply lines come in a variety of materials, including copper, stainless steel, and braided flexible tubing, and are used to deliver water to the fixture.
Supply lines are an essential component of any plumbing system, as they provide the final connection between the fixture and the water source. They are typically easy to install and can be replaced if they become worn or damaged. When choosing a supply line, it's important to select one that is the correct size and material for your specific plumbing setup.