A registry maintains a database of all domain names registered to a top-level domain (TLD); either a global TLD (gTLD) or a national TLD (ccTLD). The information for each domain includes the nameservers associated with that domain. The registry also manages the registration of domain names it of responsible for, policies of domain name allocation, operates its domain, resolves disputes and may impose third level domains, like .co.uk. A registry's authority over a set of domain names is allocated by IANA, the Internet Assigned Numbers Authority, which manages the underlying structure of the Internet.
Examples of registries include Nominet (.uk domains), DENIC (.de domains), which are both national ccTLD registries and Verisign who operates gTLDs like .COM/.NET