The standard "home" page for a site is the domain name and the base/root file (usually "index." along with the file type "htm" or "html"). In this case, Stu uses a PHP script (index.php) to point to the rest of the site. By using anything else ("/weathercat" or simply "/"), the server is probably set up to direct any 404 errors to the page you are seeing. By not specifying "/index.php" you may not get to the actual page(s) of a site where there would normally be navigation links to all other pages.