A whois lookup provides details about that domain name, including the name of the registrar, the state or country where it is registered, and the name of the organization or individual who owns it. whois tools also provide interesting details such as the date created, and the date updated. For example, if you do a whois search of cars.com, you will see the registration organization, registration country, that it was first registered on February 11, 1998, and that it was last updated on April 23, 2019. If anything is changed in the whois it will change the updated date. That could be the middle initial of an owner or a change in registrar to a new server.