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

Results forwebdisk.colman.tk

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-07-23T01:01:48.25	2020-07-23T00:00:00	2020-10-21T23:59:59	colman.tk	webdisk.colman.tk	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-07-23T01:01:47.78	2020-07-23T00:00:00	2020-10-21T23:59:59	colman.tk	webdisk.colman.tk	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-07-11T08:14:30.325	2020-07-11T00:00:00	2020-10-09T23:59:59	colman.tk	webdisk.colman.tk	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-07-11T08:14:30.008	2020-07-11T00:00:00	2020-10-09T23:59:59	colman.tk	webdisk.colman.tk	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"