.. to refer to it. The address points to an address server.

 "DNS for people", like dynamic DNS, like running an LDAP server, except the
 thing being looked up is an ID Record.

 Note that this service is totally separate from carrying the actual email
 messages. I can run an address server on my domain with minimal bandwidth
 and storage requirements. This makes it cheaper to get into the business of
 renting cool, stable, memorable names to people who can then choose their
 own means of actually receiving their messages.

 Once you get the ID Record, you don't need the address any more.