WhoIS is basically a query and response protocol that is commonly for querying databases that store the registered users of an Internet resource like an IP address block or domain name. When you run a site through this tool, the tool will return WhoIS registration results for a domain name. You can see several information such as when the domain name was registered, who is registered, when it expires, etc. Sometimes, you will be able to get more information by going to the registrar’s site.
WhoIS services are generally communicated via the Transmission Control Protocol (TPC). The application is quite easy to use. In the past WhoIS was performed with an application known as command line. Today, however, many alternative web based tools can be found. The database of WhoIS is made up of a set of text records for every record, which consists of several items of information regarding the resource itself.
The main function of WhoIS utility is to let users get full info regarding a registered domain. The WhoIS Lookup tool supports both country code domains and generic domains. The tool typically does not require any installation process. It is readily available online and can be used for free.