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

Results forwebdisk.srgrouprealhyd.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-08-30T09:33:26.627	2020-08-30T08:33:26	2020-11-28T08:33:26	webdisk.srgrouprealhyd.com	webdisk.srgrouprealhyd.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-30T09:33:26.388	2020-08-30T08:33:26	2020-11-28T08:33:26	webdisk.srgrouprealhyd.com	webdisk.srgrouprealhyd.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-30T09:41:48.951	2020-06-30T08:41:48	2020-09-28T08:41:48	srgrouprealhyd.com	webdisk.srgrouprealhyd.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-30T09:41:48.791	2020-06-30T08:41:48	2020-09-28T08:41:48	srgrouprealhyd.com	webdisk.srgrouprealhyd.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3