I avoid teaching the term ‘UX.’ It means too many things to too many different people. Instead I focus on individual skills. Once you understand the individual skills, you can assemble them into a composite system without blurring them together. For software design, the core skill among all user-facing concerns is user interface design.
I completely agree. I’ve long been confused by what UX really is but the essence of the experience is the user interface. User experience can mean so many things but it’s what you do with the user interface that really encapsulates everything and can create great experiences for the user.
For people who make software, I recommend starting with a strong understanding of UI by itself. These fundamentals can take you very far.