On the client end:
Host: www.hoboes.com
Host: hoboes.com
Host: www.godsmonsters.com
Asking for http://www.hoboes.com/ is just like asking for http://216.92.252.156/; the client adds Host: www.hoboes.com (or www.godsmonsters.com) to let the server know which hostname is being requested. Before HTTP/1.1, every hostname had to have its own IP address.
In HTTP Client, you can set “Host” to each of the above examples and get a different page back each time. The IP address is the same in each case; the server looks at the Host header to see which hostname the browser wants to see.