Whois

The most common use of whois is for looking up domain names. This may be for checking available domain names before registering or to locate information on the domain name registrant.
The whois server for domain registration records are maintained by the organization authorized to register domain names. This depends on the specific domain name extension. There are a number of registrars for the popular Com, Net and Org domains. This means that the actual domain records are generally not available from a single whois server.

Domain Whois by 101register.us