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

Results for*.bigdatau.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-03-23T12:38:50.248	2020-03-21T00:00:00	2021-03-22T12:00:00	bigdatau.com	*.bigdatau.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2020-03-23T12:38:50.248	2020-03-21T00:00:00	2021-03-22T12:00:00	bigdatau.com	*.bigdatau.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2020-03-21T05:07:27.602	2020-03-21T00:00:00	2021-03-22T12:00:00	bigdatau.com	*.bigdatau.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2020-03-21T05:07:27.602	2020-03-21T00:00:00	2021-03-22T12:00:00	bigdatau.com	*.bigdatau.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1