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

Results forwebdisk.manage.mariawebtech.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-03-29T10:19:58.622	2019-03-29T09:19:58	2019-06-27T09:19:58	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-29T10:19:58.217	2019-03-29T09:19:58	2019-06-27T09:19:58	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-01-29T18:58:45.129	2019-01-29T17:58:43	2019-04-29T17:58:43	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-01-29T18:58:43.954	2019-01-29T17:58:43	2019-04-29T17:58:43	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-02T17:31:26.849	2018-12-02T16:31:25	2019-03-02T16:31:25	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-02T17:31:25.9	2018-12-02T16:31:25	2019-03-02T16:31:25	manage.mariawebtech.com	webdisk.manage.mariawebtech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3