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

Results for*.shortwave.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-12-26T18:11:00.934	2019-12-23T00:00:00	2020-12-23T12:00:00	shortwave.com	*.shortwave.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2019-12-26T18:11:00.934	2019-12-23T00:00:00	2020-12-23T12:00:00	shortwave.com	*.shortwave.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2019-12-23T10:49:45.224	2019-12-23T00:00:00	2020-12-23T12:00:00	shortwave.com	*.shortwave.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1
2019-12-23T10:49:45.224	2019-12-23T00:00:00	2020-12-23T12:00:00	shortwave.com	*.shortwave.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1