This document defines key terms related to domain name registration: - A registry maintains the centralized database for top-level domains like .com and assigns them to registrars. NSI Registry currently serves this role. - A registrar is authorized by ICANN to register domain names for customers and submits them to the registry database. - A registrant is the legal owner of a registered domain name and enters an agreement with their chosen registrar. - ICANN is a non-profit responsible for coordinating the domain name system, IP address allocation, and root server management. Registrars must obtain ICANN accreditation to operate.