When you perform a WHOIS search on a domain, you will be able to find a plethora of domain registration information. For example, if you are looking up a domain that is privately owned, the WHOIS database contains the full name, address, telephone number, and email address of the registered owner of the domain.
If the domain is owned by a business, the company name, address, email, and telephone number are listed. There may also be areas for a domain administrator, technical administrator, and other contacts. The expiration date of the registration period is also listed.