All the domain names are mapped into their Internet Protocol (IP) addresses.
For any domain you can find the corresponding IP address easily.
Domaintools.com provides support to search every top level domain. Enter the domain name and click on Lookup and you get a result like this.
You get results for the Whois record, site profile, Registration and Server stats. Under the server stats tab you can see the IP address, IP location and Server type. Also you see a thumbnail of the site.