g1smd - 12:36 pm on Jan 9, 2013 (gmt 0)
DirectoryIndex index.htm ensures that when a user requests
example.com/folder/ - the canonical URL for a folder or for the index page in a folder - the server uses the content of the index.htm file in that folder to fulfill that request, without telling the user what that file is actually called.
URLs are a reference system used "out there" on the web. Filenames are a reference system used "here" inside the server. The two are not at all the same thing, merely related by the actions of the server software and how it is configured.
DirectorySlash directive is also relevant. When user requests
example.com/folder for folder name that exists, the server will send a redirect telling the browser to make a new request for
The site should link to
href="/folder/" each time.
Make sure you install a local copy of Apache so you can fully test your site as http ://localhost/ or http ://127.0.0.1/ too.