To begin using MUI in your React application, you need to install the core package. Open your terminal in the root directory of your React project and run the following command:

npm install @mui/material @emotion/react @emotion/styled

This command installs MUI's core components along with its required styling dependencies. Once installed, you can start importing MUI components directly into your React files. For example, you might want to add a button or some styled text to your interface. Here is how you can import and use the Button and Typography components in your main App component:

In this example, you first import the components you want to use from @mui/material. The <CssBaseline /> component is included at the top of your component tree. This is an important step when working with MUI.

The CssBaseline component plays a crucial role in ensuring that your application looks consistent across different browsers. It provides a set of CSS resets and sensible defaults, removing browser inconsistencies and giving you a predictable foundation for your styles. By including CssBaseline once, typically near the root of your app, you avoid unexpected spacing, font, and color issues that might otherwise arise from browser defaults. This helps you focus on designing your interface without worrying about cross-browser quirks.

With MUI installed and the CSS baseline in place, you can start using MUI components to build your interface. In the earlier example, the Button component renders a styled button with MUI's default theme, and the Typography component displays a heading with consistent sizing and spacing. These components are highly customizable and provide a solid starting point for building modern, accessible interfaces in React.