The WHOIS system is method for people to find out info about domain names. You can see WHOIS info for zimouniqueplan.com above.
As you can see, you can find out when was zimouniqueplan.com registered, when zimouniqueplan.com will expire and last update of WHOIS database for zimouniqueplan.com registrar, tech, admin and registrant info for zimouniqueplan.com
You need to know that domain registrar companies offer to website/domain owners WHOIS privacy protection service. With this service domain owners hide their personal information from public view and protect their identity and privacy.
If you are webmaster, you can with WHOIS domain see updated domain name servers. Name server changes take up to 48 hours to fully start working.
If you want to buy some specific domain, with WHOIS check you can find out when the domain is expiring.