Addon domains allow you to have more than one independent website sharing the resources of your hosting account. Addon domain hosting is similar to virtualization. You can host multiple domains or multiple websites on a single account which are basically set up as subdomains on the main domain but the domains you add as an addon domain gets parked on top of the subdomain. You can see a website of the subdomain when you type your addon domain in your browser but the URL never changes as it continues with your addon domain in the browser.
You can have multiple domain names pointing to your site. This is a great way to increase your online visibility. The parked domain on the main domain shows the website of the main domain. Similarly parked domain on the subdomain would show the website of a subdomain.
Examples of parked domains are:
Apache configuration needs to know what directory to call when someone opens a particular website in the browser and in the case of addon domains, it will load the subdomain. Your addon domain is added as an alias for that subdomain.
From a user perspective, an addon domain functions just like any other domain. You can register and set up an addon domain under your existing web hosting account. So when your visitors type http://www.yourdomain.com in their browser, they will be transported to the new site. The difference between a parked domain and an addon domain from a web user’s perspective is that with a parked domain the URL in the address bar will change to the physical location of the page as the page loads.
For example, if you type http://www.abc.com, that domain won’t remain in the browser address bar but will change to http://www.domain.com/abc/index.html as soon as the page is displayed.