A user persona in product design serves as a detailed representation of a target user, including demographic information, preferences, behaviors, and pain points. The purpose of a user persona is to guide the design and development process by ensuring that the final product aligns with the needs and expectations of its intended audience. By utilizing user personas, teams can create user-centered designs that enhance usability and overall user experience. Personas help to clarify goals and inform decisions throughout the development lifecycle, fostering empathy for the end-user.