Domain

Internet standard. A human-readable branding for an individual or organization's presense on the internet. RFC 1034 defines domains and the Domain Name System (DNS).

This differs from a fully qualified domain name (FQDN). An FQDN includes both a hostname and a domain, which resolve to an IP address.

An organization uses their domain to associate any internet presence to their organization from websites like example.com to email addresses like alex@example.com.

A domain covers a domain name space: all internet hosts that an organization manages.

To learn more, see the Twilio Email Infrastructure Guide.