Parked domains are simply secondary domains that point to your primary domain. They will serve the same files as your primary domain and otherwise function the same. Parked domains are often used by businesses that want to have more than one web address for advertising purposes.

In other words, a Parked Domain is one that points to another existing domain under which it is parked.

For example: Let us consider that you have hosted example.com

Now you are parking new domain example.net under example.com.

From now on when ever you type your parked domain name example.net in the browser, it will display the pages of example.com. The browser shows the url example.net.