If you wish to point a domain address that you have to some other domain address or subdomain, the best way to do this would be to use a CNAME record. By creating such a record, the domain being pointed loses all of its records (A, MX, and so on) and instead, it takes the A record of the domain it is pointed to. In this way, if you are using a web design service by some company that gives you a subdomain, you can use an actual domain and not only will it be pointed to the website that you've set up, but it will also be displayed in the browser address bar at all times. Alternative possible uses of a CNAME record are to point all the targeted traffic from different subdomains to their main domain address, or to use the webmail service of your hosting provider by using webmail.your-doman.com, for example. The latter will work only by creating a CNAME record for a subdomain because this type of a record created for the main domain address renders it impossible to use email addresses.