If you want to point a domain name that you have to another domain name or subdomain, the best way to do this would be to use a CNAME record. By creating such a record, the domain being forwarded loses all of its records (A, MX, and so forth) and instead, it takes the A record of the domain name it's directed to. By doing this, 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 redirected to the site you have set up, but it will also be displayed in the web browser address bar at all times. Other possible uses of a CNAME record are to direct all the traffic from different subdomains to their main domain, or to use the webmail service of your webhosting company by using webmail.your-doman.com, for instance. The latter will work only by creating a CNAME record for a subdomain because this kind of a record set up for the main domain renders it impossible to use e-mail addresses.
