Domain Nameservers (DNS)
Having set up my web space, I needed to get the domain name to point at the space and this is done by changing the DNS records at the site that hosts the domain (that is, the domain name rather than the actual space for the web site).
You get the correct nameserver records from the web space provider (HostGator in my case) and they look like this
NameServer1: ns237.websitewelcome.com
NameServer2: ns238.websitewelcome.com
Just type these into the appropriate boxes with the domain name host and it will tell everyone that your URL now points to the new web space. (there are lots of different nameservers all round that maintain a current database linking site names to web space IP addresses and it can take up to 48 hours for the new relationship to propagate everywhere).