These two terms get used almost interchangeably in casual conversation, but they describe different roles in the domain system.

A registry operates a specific top-level domain (TLD) at the infrastructure level: it maintains the authoritative database of every domain registered under that TLD. Verisign, for example, is the registry for .com and .net .

A registrar is the company that sells domain registrations to the public and is accredited to interact with registries on customers' behalf; NameBright is a registrar. When you register a domain through NameBright, NameBright is submitting that registration to the appropriate registry on your behalf; you never interact with the registry directly.

Most registrars license standard backend systems from third-party providers to handle this registry interaction rather than building their own. NameBright is a notable exception, running its own backend systems rather than a licensed third-party platform.