What does UX design stand for?

The correct designation for UX design is "User Experience design." This term encapsulates the overall experience a user has when interacting with a product or service, particularly focusing on the design of systems and interfaces that are user-friendly, efficient, and enjoyable.

User Experience design involves understanding the needs, behaviors, and motivations of users to create solutions that provide meaningful and relevant experiences. It encompasses aspects like usability, accessibility, and interaction design, ensuring that a product is not only functional but also intuitive and engaging for the user.

In contrast, the other options like User Expansion design, Universal Experience design, and Unified Experience design do not accurately reflect the commonly accepted concept in the field of design. They imply different areas or focuses that are not recognized in the context of UX design, which is specifically geared toward optimizing how users interact with products and services.