The pages.xml file and any .page.xml file is Seam's way of describing:
1. RESTful (non-Faces) pages – That is, what to do with the URL parameters for a GET request.
2. View restrictions – Restrict users from viewing pages based on an EL expression.
3. Page actions – Invoke EL expressions whenever a page is accessed (RESTful or not).
4. Page flow – The Seam <navigation> elements can replace the ordinary JSF navigation rules.