It can be anything! An apex, subdomain, or even a URL.

Results fordns2.robhost.de

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2018-02-11T02:46:44.248	2018-02-08T00:00:00	2021-02-07T23:59:59	*.robhost.de	*.robhost.de	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
2014-09-11T16:47:02.505	2014-02-23T00:00:00	2018-02-23T23:59:59	*.robhost.de	*.robhost.de	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
2014-04-17T12:40:41.596	2014-02-23T00:00:00	2018-02-23T23:59:59	*.robhost.de	*.robhost.de	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=PositiveSSL CA 2
2014-02-25T12:37:06.28	2014-02-23T00:00:00	2018-02-23T23:59:59	*.robhost.de	*.robhost.de	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=PositiveSSL CA 2
2013-04-08T17:41:22.479	2012-03-05T22:20:02	2014-03-06T22:20:02	*.robhost.de	*.robhost.de	O=AlphaSSL, CN=AlphaSSL CA - G2