This document explains the differences between UX (user experience) and UI (user interface) design, highlighting that UX is about the overall experience a user has with a product, while UI focuses on the specific screens and elements that users interact with. It emphasizes the importance of a UX designer in creating useful and engaging experiences through various methods such as prototyping and usability testing. The document also mentions the tools typically used by UX designers to improve user interaction with digital products.