The primary focus of user research in product development is to understand the needs, preferences, and behaviors of target users. This involves gathering insights through various methods, such as interviews, surveys, and usability testing, to inform design and functionality decisions. By empathizing with users, teams can identify pain points and opportunities, ensuring that the product addresses real-world problems effectively. Ultimately, user research drives user-centered design, resulting in products that offer enhanced experiences and increased satisfaction, leading to better market adoption and success.