Meaning
User Interface; the visual, interactive, and graphic touchpoints through which a human navigates and controls a digital device or software.
Three examples from work
Design review
DesignerWe simplified the checkout UI to reduce cognitive overload.
POThe clean contrast on the primary button looks great.
Bug report
QAThere is a minor UI glitch where the dropdown overlaps the search bar on mobile.
Frontend DevI'll adjust the z-index and padding in CSS.
Design system
LeadUsing standardized UI components ensures visual consistency across the app.
DevIt also saves developers hours of writing custom styles.
Pronounce each letter: 'U-I'. While UI refers to the visual presentation (look), UX refers to the overall interaction feel and ease of use.