What is the role of DirectoryIndex in .htaccess file
Whenever you enter a URL in the browser, that URL is pointing to a specific file on the web server. For the main parent domain every web server has default page settings. For example if i type www.programmingbaba.com the default page will be index.php. So typing www.programmingbaba.com or www.programmingbaba.com/index.php will open the same page.
There are some default conventions which usually each web servers know these days. For example if your home page is index.php or index.html. You don’t need to do any settings to tell the server that these are my default home pages. If you want to customize your default page or if your server is not configured or if you are getting the following kind of response when you open your main domain
and you want to set yourself a default page for your website. You can use DirectoryIndex tag in your .htaccess file to configure your default pages.
Simply add the following line in your .htaccess file
DirectoryIndex index.html index.php default.aspx
simple keep on adding all default pages which you want to configure.