Here are some of the differences between React.js and React Native:

• React Native has its own special JSX syntax to build UI components. By default, it does not make use of CSS and HTML like React.js.
• React Native relies on some special libraries to interface with mobile devices. For example, you need to use React-Native-specific packages to write code around a phone camera or accelerometer.
• Deploying React Native apps is a different experience to deploying React.js, since the deployment into mobile device with all its app rules.