If you would like to point a domain name that you have to another domain name or subdomain, one of the ways to do that would be to use a CNAME record. By setting up such a record, the domain being pointed loses all its records (A, MX, etc) and instead, it takes the A record of the domain address it's forwarded to. In this 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 forwarded to the website that you have set up, but it'll also be displayed in the web browser address bar at all times. Alternative possible uses of a CNAME record are to forward all of the targeted traffic from different subdomains to their main Internet domain, or to use the webmail service of your hosting company by using webmail.your-doman.com, for instance. The latter will work only by setting up a CNAME record for a subdomain simply because this kind of a record set up for the main domain name renders it impossible to use email addresses.