Name Changeing

When I first started with dreamhosters as a Rookie I assumed that i had to use a domain name like , So i have built my joomla site , now I have discovered that i was wrong I could have used

I have seen this done once but cant find out how I remember we copied the site to local machine created the new domain on the dreamhost panel and uploaded the files… then was a config file we had to change… but like I said I cant remember and I am sure there is more to it

Any help would be appreciated

Edit the configuration.php file