What is the purpose of using plumbing pipe dope and how does it help in sealing and lubricating threaded connections in plumbing systems?

Plumbing pipe dope is used to seal and lubricate threaded connections in plumbing systems. It helps create a tight seal to prevent leaks and also makes it easier to tighten and loosen connections. The purpose of using pipe dope is to ensure a secure and leak-free connection in plumbing systems.