Tim Green wrote:
No, you shouldn't need to transfer the domain. Your domain registration points to a DNS server or two. This then will direct look ups for things like www.yourdomain.com to a webserver, and the webserver needs to be configured to differentiate between www.yourdomain.com and www.somebodyelsesdomain.com.
Depending on the type of site, having your DNS on a different server, indeed with a different provider, from your website can have some useful benefits. In the event of a major hardware failure at the web host, for example, you can use the DNS to redirect traffic to an alternative host pretty quickly (how quickly depends on DNS reload times and TTLs, and 24-48 hrs isn't uncommon but can be improved upon). DNS should be on at least two hosts anyway so is not so sensitive to a single failure (unless, as happened with our ISP recently, both DNS are on the same network behind the same PSU that goes pop, but that just means you should pick a decent ISP).