REGISTRY , REGISTRAR & REGISTRANT
In simple Terms,
REGISTRY: registry is a Top Authority manage Domain Database and facilitate to sell and manage domains through selected REGISTRAR's
REGISTRAR: Registrar is preferably a company appointed by REGISTRY to sell domains, maintain domains and provide any associated services
REGISTRANT : Registrant is an Individual or an organization buy domains from a registrar for a specific period, or can be called a LICENSEE