There are various ways to direct a domain address to another domain or subdomain and one of them is by creating a CNAME record. When you own a domain and you've developed a website using some on-line service which supplies you with a service subdomain, you could easily link the two by creating a CNAME record for your-domain.com that redirects to subdomain.provider.com. What you'll achieve with this is that www.your-domain.com is going to be in the browser address bar while it opens the already mentioned website from the servers of the third-party company. You should know that if you create a CNAME record, any other records your domain may have will stop functioning, so you can't have both a CNAME record pointing to one provider and working email addresses with another. The CNAME record is always an alpha string, not a number, and sometimes further configuration may be necessary with the other company.