The Whois Tool is meant to help you find out information about a domain, like who owns it, name servers and other information.
It's basicaly a protocol used to query databases for various information ( domains, IP blocks, AS systems and others ).
You can use this to query specific whois servers if you're wondering about information about new .tld's.
You can use the api to query
curl https://serverstuff.info/api/whois?host=<query>&whoishost=<server> the [whoishost] part is optional.