Not completely, but better
You must think of DNS as something like an addressbook. Its useless if you ask "where is the address book" and the actual location of the address book is noted in the address book itself.
if you have aaa.org and bbb.org:
Configure aaa.org at your registrars DNS, set an A-Record ns1.aaa.org pointing to your server IP and an A-Record ns2.aaa.org, pointing to your secondary DNS servers IP or in case you own only one server, let ns2.aaa.org point also to your servers IP address.
Now if you get domain bbb.org, you can set the primary DNS to ns1.aaa.org and the secondary DNS to ns2.aaa.org.
On your server, you create a primary DNS Record for bbb.org.
If you enter now bbb.org in a browser, the nameserver on your server will be asked for the correct IP for bbb.org and its subdomains.