DreamHost DNS overview https://help.dreamhost.com/hc/en-us/articles/215413857-DreamHost-DNS-overview
1. whois
Using a domain managed by a third-party registrar You can still host your domain at DreamHost if it's registered at a different company. However, you will need to point your DNS to DreamHost in order for it to function. View the following article for information on how to adjust your DNS to point to DreamHost after setting up your domain in the panel.
How to host your domain at DreamHost if it is registered at another company https://help.dreamhost.com/hc/en-us/articles/360004289812-How-to-host-your-domain-at-DreamHost-if-it-is-registered-at-another-company