UX design could be a complex set of activities in several dimensions:

• Information architecture or menu structure,
• Interaction principles including navigation and data manipulation,
• Screen layout that specifies a number, size and place of elements on the screen,
• Visual design or look-and-feel,
• Transitions and animation,
• Branding.

In different projects you can work on one or several of those dimensions simultaneously. And while performing those activities you have to consider how the created design influences users’ emotions, feeling, cognition… the product aims to invoke.