Supply line
The flexible hose feeding water to a fixture like a toilet or washer.
Supply lines are the braided or rubber hoses connecting your shutoff valves to toilets, faucets, washing machines, and ice makers. Cheap rubber ones fail with age and are a top cause of catastrophic indoor flooding — a burst washer hose can dump hundreds of gallons an hour. Swap rubber for braided stainless steel and glance at them yearly.