Tailwind CSS is a utility-first CSS framework that provides a large set of low-level utility classes to build custom designs without writing CSS. It focuses on rapidly building custom user interfaces by applying predefined classes directly in the HTML.

The tailwind.config.js file is used to customize Tailwind default configuration, such as defining custom colors, spacing, fonts, and breakpoints. It allows you to extend or modify Tailwinds utility classes according to the specific needs of your project.

Tailwind CSS is a utility-first framework with single-purpose classes that give you full control over your design. In contrast, Bootstrap is a component-based framework with prebuilt components and layout styles. Tailwind is highly customizable, while Bootstrap provides out-of-the-box components that are easier to use but less flexible for custom designs.