React vs ReactDom

When building web applications in React, you use two packages—react and react-dom.

The difference between react and react-dom

The react package holds the react source for components, state, props and all the code that is react.

The react-dom package as the name implies is the glue between React and the DOM. Often, you will only use it for one single thing: mounting your application to the index.html file with ReactDOM.render().

Mounting and Unmounting

Mount - Mounting and Unmounting File Systems. Before you can access the files on a file system, you need to mount the file system. Mounting a file system attaches that file system to a directory (mount point) and makes it available to the system. The root ( / ) file system is always mounted.

Unmounting - Unmounting a disk makes it inaccessible by the computer. Of course, in order for a disk to be unmounted, it must first be mounted. When a disk is mounted, it is active and the computer can access its contents. Since unmounting a disk prevents the computer from accessing it, there is no risk of the disk being disconnected in the middle of a data transfer.

Why separate them?

The reason React and ReactDOM were split into two libraries was due to the arrival of React Native (A react platform for mobile development).

Conclusion

React components are such a great way to organize UI that it has now spread to mobile to react is used in web and in mobile. react-dom is used only in web apps.