Hi @Ankit,
Currently, there is no visual way of comparing two contents, however, you can download JSON for the contents and compare them, for downloading JSON you can refer to our forum post Download/uploading content. You can also submit a feature request for the same at Builder.io Ideas
In Builder, you can create as many versions of content entries as you like. Creating multiple versions allows you to test different experiences, target different versions to various audiences, revert back to previous iterations, and more.
There are two main ways to manage versions with Builder: the Versions Tab in the Visual Editor or directly from the Content List Tab.
However, the recommended way to create a version is using the Versions Tab