UI icons (User Interface icons) are visual symbols used in digital interfaces to represent actions, features, navigation elements, or information. They help users understand and interact with applications and websites more intuitively.

UI icon purposes:

- Navigation: Help users move through interfaces

- Actions: Represent functions and commands

- Status: Show system or content states

- Information: Convey information quickly

- Aesthetics: Enhance visual design

Types of UI icons:

- Navigation icons: Menu, home, back buttons

- Action icons: Save, delete, edit, share

- Status icons: Loading, error, success indicators

- Content icons: File types, media players

- Social icons: Share, like, comment buttons

UI icon design principles:

- Clarity: Immediately understandable

- Consistency: Uniform style throughout

- Simplicity: Clean, uncluttered designs

- Recognition: Use familiar symbols

- Accessibility: Work for diverse users

UI icon best practices:

- Standard symbols: Use recognized conventions

- Consistent style: Match design system

- Appropriate size: Readable at intended size

- Color coding: Use color meaningfully

- Hover states: Provide feedback

3D UI icons add:

- Visual interest and depth

- Modern, engaging appearance

- Brand differentiation

- Enhanced user experience

- Professional polish

Well-designed UI icons make interfaces more intuitive, reducing the need for text labels and improving user experience.