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

Results forowa.mba.wfu.edu

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2016-10-01T12:10:07.244	2005-01-14T13:48:33	2007-03-16T13:48:33	owa.mba.wfu.edu	owa.mba.wfu.edu	C=US, ST=UT, L=Salt Lake City, O=The USERTRUST Network, OU=http://www.usertrust.com, CN=UTN-USERFirst-Network Applications
2016-09-20T20:24:44.145	2009-03-25T17:30:46	2011-05-25T17:30:46	owa.mba.wfu.edu	owa.mba.wfu.edu	C=US, O=Equifax Secure Inc., CN=Equifax Secure Global eBusiness CA-1
2013-05-22T10:14:56.492	2013-05-08T08:06:56	2014-07-10T16:58:38	owa.mba.wfu.edu	owa.mba.wfu.edu	C=US, O="GeoTrust, Inc.", CN=RapidSSL CA
2013-04-27T03:06:23.221	2011-05-10T07:22:02	2013-06-11T15:31:52	owa.mba.wfu.edu	owa.mba.wfu.edu	C=US, O="GeoTrust, Inc.", CN=RapidSSL CA