If you would like to forward a domain that you have to a different domain name or subdomain, the best way to do that would be to use a CNAME record. By setting up such a record, the domain address being redirected loses all of its records (A, MX, and so on) and instead, it takes the A record of the domain name it's redirected to. That way, if you are using a web design service by some provider 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'll also appear in the browser address bar at all times. Alternative possible uses of a CNAME record are to forward all of the traffic from different subdomains to their main Internet domain, or to use the webmail service of your webhosting company by using webmail.your-doman.com, for example. The latter will work only by setting up a CNAME record for a subdomain simply because such a record set up for the main domain renders it impossible to use email addresses.