A browser prefer a few larger files over many small files. What I mean by “prefer” is that it is faster if you do it this way. There is of course a limit to how large those files should be, webpack starts to warn you if you pass a few hundred KB. If you have too many small files, then your browser spend more time opening connections to your web server than it does on downloading them, but if they are too big your bandwidth are not used efficiently enough; if the total is a megabyte, then it would probably be faster to download it as 10 100kb files, instead of one 1014kb files or 1024 1kb files.
You can also use webpack to solve one of the most annoying problems with web development, after the browsers started to become very aggressive in caching resources. That is: you updated index.js, but you can’t see the changes it your browser. Or you have updated the server, but you need to get a customer to clear their caches. That’s not going to happen, right?
No code or samples in this one, but I’m probably going to show how I’m doing stuff with webpack in the near future.