Registry – A registry is an organization or company that keeps a record of all domains under a certain extension. For example, Verisign is the registry that manages all.Com extension domain names. In essence, a registry is a supplier to the registrar.
Registrar – A registrar is a company that manages the buying and selling of domain names. All registrars are credited by the overseeing entity called ICANN (Internet Corporation for Assigned Names and Numbers). To register a domain, you will typically work with a registrar service, such as GoDaddy.com, NetworkSolutions.com, or Web.com. However, you don’t need to choose between one of the mainstream registrars. There are hundreds, if not thousands of other registrars that offer many of the same services and at lower prices.
Registrant – This is the consumer (business, individual, or organization).