Domain masking is a method of hiding the actual URL of a site. For example, if you have domainA.com and domainB.com, you can show visitors the content of domainA.com but domainB.com still shows as the address in their browser.
Please note, search engines will see this as duplicate content (same content on both domainA.com and domainB.com) and this could affect search engine rankings for one or both of your sites. Using 301 redirects is the generally recommended for pointing one domain to another.
If domainA.com is your main domain, you can create domainB.com as a Parked domain. This will keep the URL of domainB.com in the browser address bar, but serve the content of domainA.com.
If domainA.com and domainB.com are both Addon domains, when you create domainB.com as an Addon, make sure you set the document root to be the same folder as domainA.com
Friendly URLs in Content Management Systems
There may be some cases where you are simply trying to create "friendlier" URLs in your site. If you're using a Content Management System (CMS) such as WordPress, Joomla or Drupal, there are built-in methods in these systems for creating these types of URLs. These types of URLs are called different things depending on your CMS. For example:
Other Friendly URLs
You can also make edits to your .htaccess file which will "rewrite" your URLs. Here are two examples:
If you wanted to show the content of:
But you wanted the URL to look like:
You could put this code in your .htaccess file:
RewriteRule ^subdirectory1\/?$ \/subdirectory1\/subdirectory2\/
If you want to hide file extensions in your URLs. For instance:
Show content from:
But you want the URL to look like:
Put this in your .htaccess file:
There are several options for URL masking, you may want to expermient with the different options to see which works best for your site.