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

Results forwww.server.linuxadminonline.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-04-18T06:09:29.02	2019-04-18T00:00:00	2020-04-17T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2019-04-18T06:09:09.21	2019-04-18T00:00:00	2020-04-17T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-09-23T22:19:43.229	2018-09-23T00:00:00	2019-09-23T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-09-23T22:19:25.557	2018-09-23T00:00:00	2019-09-23T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-05-26T21:26:17.878	2018-02-14T00:00:00	2019-02-14T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-01-15T02:34:09.525	2017-02-23T00:00:00	2018-02-23T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2018-01-11T20:45:46.274	2017-05-24T00:00:00	2018-05-24T23:59:59	server.linuxadminonline.com	www.server.linuxadminonline.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"