If you would like to direct a domain name that you have to some other domain or subdomain, the best way to do that would be to use a CNAME record. By creating such a record, the domain name being redirected loses all its records (A, MX, and so forth) and instead, it takes the A record of the domain it is pointed to. That way, if you use a web design service by some company that gives you a subdomain, you can use an actual domain and not only will it be directed to the site that you have set up, but it'll also be displayed in the browser address bar at all times. Other possible uses of a CNAME record are to direct all of the targeted traffic from different subdomains to their main domain name, or to use the webmail service of your hosting 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.