Question regarding domain names and web servers

Question

Say there is a website, www.website1.com, that is hosted on a web server, web server A. Is it possible to have another website, www.something.website1.com on a different web server, web server B? Or is the www.something.website1.com still considered a sub domain of www.website1.com, and must be hosted on the same web server, A?

For clarification: www.website1.com is hosted on a third party web server, but a client wants us to host www.something.website1.com on one of our own web servers, NOT the third party. Is this possible?

Answer 1

This is a DNS change; where ever the DNS for website1.com is handled you want to add an A record for www.something.website1.com to point to the new IP address.

Then on the Server B, of course, you need to let the http server (Apache, lighttpd, etc) know that it is serving for that name.

Answer 2

Yes It's possible. You just need to ask your provider to have the URL www.something.website1.com point to your second website on the server B.

It's like having a website and a webmail with different providers.