In detail
UI design determines how a product looks and how its controls behave. Consistent UI, usually managed through a design system, makes products easier to learn and cheaper to extend.
UI is often confused with UX; UI is the surface, UX is the whole experience.
How this relates to our work
UI comes up most often in our app development work. Mobile applications for customers and field teams, built natively or cross-platform depending on what the product needs.