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

Results forwebdisk.aboutopia.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2022-04-18T16:13:39.777	2021-07-29T00:00:00	2022-07-29T23:59:59	aboutopia.com	*.aboutopia.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2021-07-29T14:20:55.904	2021-07-29T00:00:00	2022-07-29T23:59:59	aboutopia.com	*.aboutopia.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2020-12-12T06:59:14.306	2020-12-12T00:00:00	2021-03-12T23:59:59	aboutopia.com	webdisk.aboutopia.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-12-12T06:59:13.989	2020-12-12T00:00:00	2021-03-12T23:59:59	aboutopia.com	webdisk.aboutopia.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-11-27T04:59:03.946	2020-11-27T00:00:00	2021-02-25T23:59:59	aboutopia.hostcrossing.com	webdisk.aboutopia.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-11-27T04:59:03.537	2020-11-27T00:00:00	2021-02-25T23:59:59	aboutopia.hostcrossing.com	webdisk.aboutopia.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"