Tailwind CSS is a modern CSS framework that operates in a different manner from traditional CSS frameworks like Bootstrap or Foundation. Instead of providing pre-defined components and styles, Tailwind CSS gives you a set of low-level utility classes that allow you to rapidly create custom designs.

Here are some key features of Tailwind CSS:

1. Utility-First Approach: Tailwind CSS focuses on using utility classes to control styling of elements directly in HTML. These classes provide granular control over properties such as size, spacing, colors, and fonts.

2. Fully Customizable: Tailwind CSS is fully customizable, allowing you to create your own themes and customize the design completely without having to write your own CSS code.

3. Mobile-First: Tailwind CSS is designed from the ground up to be responsive and well-suited for mobile application development. It provides specific utility classes for working with different screen sizes and resolutions.

4. Extensibility: Tailwind CSS is highly extensible, offering a variety of plugins and extensions for additional functionality you may need.

5. Community and Ecosystem: Tailwind CSS has a growing community of developers and a rich selection of resources such as tutorials, templates, and tools to help you use the framework.

Overall, Tailwind CSS enables developers to quickly and efficiently create modern designs by leveraging a wide array of pre-defined utility classes while also providing flexibility and customizability.