There are lots of ways to direct a domain name to an alternative domain or subdomain and one of them is by setting up a CNAME record. If you own a domain and you have set up a site through some online service that provides you with a service subdomain, you can easily link the two by creating a CNAME record for your-domain.com that points to subdomain.provider.com. What you are going to achieve in this way is that www.your-domain.com will be in the web browser address bar while it opens the already mentioned site from the servers of the third-party provider. You should know that if you create a CNAME record, any other records your domain name may have will stop working, so you can't have both a CNAME record directing to one provider and functioning email addresses with a different one. The CNAME record is always an alpha string, not a number, and in some cases more configuration may be necessary with the other company.