User testing is a key tool that product teams can use to gather feedback and insights about how real users interact with a product or service. By observing users as they perform tasks and interact with a product, teams can identify any usability issues and gather valuable feedback that can be used to improve the user experience. User testing can be conducted using various methods, such as usability testing, focus groups, and A/B testing, and can be done at any stage in the product development process.