What is the purpose of a tub flange and how does it contribute to the installation of a bathtub?

The purpose of a tub flange is to create a watertight seal between the bathtub and the surrounding walls. It helps prevent water from leaking behind the tub and causing damage to the walls and floor. The tub flange is typically installed during the bathtub installation process and is an important component for ensuring a secure and waterproof fit.