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

Results forwebdisk.prosetevent.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2018-11-01T00:22:53.837	2018-11-01T00:00:00	2019-01-30T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-11-01T00:22:36.419	2018-11-01T00:00:00	2019-01-30T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-08-17T00:24:47.142	2018-08-17T00:00:00	2018-11-15T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-08-17T00:24:21.313	2018-08-17T00:00:00	2018-11-15T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-06-14T00:24:57.717	2018-06-14T00:00:00	2018-09-12T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-06-14T00:24:37.542	2018-06-14T00:00:00	2018-09-12T23:59:59	prosetevent.com	webdisk.prosetevent.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"