Generally the URL of the page is corresponding to the location of that page in the package.
This makes the URL more complex. In this video we will learn how to make it clean.To create the clean URL, we will learn about the document feature
of Sitemap
it helps to decouple the package organization and corresponding URLs. So you can keep files as you wish in the package but URL still does not depend on the path of the file.
It empowers the user to give a custom URL to the page
And That also helps to give a clean URL