If you want to point a domain that you have to another domain name or subdomain, a good way to do this would be to use a CNAME record. By setting up such a record, the domain name being forwarded loses all its records (A, MX, and so on) and instead, it takes the A record of the domain address it is directed to. By doing this, 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 pointed to the website you have created, but it'll also be displayed in the browser address bar at all times. Alternative possible uses of a CNAME record are to forward all the visitors from different subdomains to their main domain address, or to use the webmail service of your hosting company by using webmail.your-doman.com, for instance. The latter will work only by creating a CNAME record for a subdomain due to the fact that such a record set up for the main domain makes it impossible to use e-mail addresses.