The answer to 'pressure regulator or pressure regulator' is that a pressure regulator and a pressure reducing valve are the same thing - a device used to control and maintain water pressure in a plumbing system. Both terms refer to the same type of component that is installed to reduce high incoming water pressure to a safe, consistent level for the home's plumbing fixtures and appliances.
Pressure regulators are essential in many homes, as they protect against damage from excessively high water pressure, which can cause leaks, burst pipes, and premature failure of faucets, washing machines, and other water-using devices. They work by automatically adjusting the water pressure to a pre-set, optimal level, typically between 40-60 PSI.