Tell about the standards of Materialize user interface.

Materialize is a front-end framework inspired by Google's Material Design. It provides ready-to-use user interface components such as buttons, forms, navigation, cards, modals, and more, that conform to Material Design standards.

Key standards implemented by Materialize include:

• Grid: A responsive 12-column grid for building flexible layouts.
• Colors: A predefined palette of Material Design colors with classes for application.
• Typography: Fonts, sizes, and styles that adhere to Material Design guidelines.
• Depth: Shadow effects to create visual hierarchy.
• Animation: Smooth and meaningful transitions and animations.
• Components: A wide range of UI components developed according to Material Design.

Main components and their features in Materialize:

Component	Features
Buttons	Various styles (flat, raised, floating), icons.
Forms	Styling input fields, selection, checkboxes, radio buttons.
Navbar	Responsive navigation bar with dropdown menus.
Cards	Containers for organizing content with shadow and rounded corners.
Modals	Dialog windows for important information or actions.
Tabs	Switching between content sections.
Collections	Styled lists of elements.
Preloaders	Loading indicators.

Example of using a button in Materialize:

<!-- Simple button -->
<a class="waves-effect waves-light btn">button</a>

<!-- Button with icon -->
<a class="btn-floating btn-large waves-effect waves-light red"><i class="material-icons">add</i></a>

Materialize promotes creating a consistent and intuitive user interface following Material Design principles. Knowledge and use of these standards are important for ensuring high-quality UI.