Parked domains are basically an alias domain name to your primary domain, it will be pointing to the same webpages as your primary domain is pointing to, i.e. multiple domains, same website.
Example:
primarydomain.com/index.htm and parkeddomain.com/index.htm will point to the same webpage "index.htm".
Update the Name Servers:
When you register a domain name with us, we set it up on our nameservers.
If you registered your domain name with another provider you must set the nameservers with your domain name registrar.
To setup a parked domain, first set the nameserver for the domain you wish to park to :
primary nameserver : ns1.elcoserv.com
secondary nameserver : ns2.elcoserv.com
Assigning the Domain Name
1. Login to your cPanel.
2. Under the Domain section press Parked Domain icon.
3. In the opened window find Create a New Parked Domain and enter the domain name.
4. Press Add Domain button.
When you finish your Domain Name will be parked to your main account.