Bundling is the technique of combining or concatenating multiple files together so that they can be delivered as one. This is a good idea when using HTTP/1.1 because the number of concurrent connections is limited. However, bundling is less necessary with HTTP/2, and in fact, it can reduce performance. The new multiplexing in HTTP/2 means that there is no longer a large penalty when you request many files instead of one, which contain all of the same content. You can take advantage of this by only delivering what is needed for a page rather than the entire client side code base for every page. Even if you selectively bundle per page, this could be inefficient.
For example, you may include a validation library for use with forms. ...