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

Results for*.ecocool.co

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-11-12T19:18:21.82	2020-11-12T18:18:21	2021-02-10T18:18:21	ecocool.co	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-11-12T19:18:21.82	2020-11-12T18:18:21	2021-02-10T18:18:21	ecocool.co	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-11-12T19:18:21.593	2020-11-12T18:18:21	2021-02-10T18:18:21	ecocool.co	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-11-12T19:18:21.593	2020-11-12T18:18:21	2021-02-10T18:18:21	ecocool.co	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-13T11:05:49.847	2020-09-13T10:05:49	2020-12-12T10:05:49	graperoom.com	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-13T11:05:49.847	2020-09-13T10:05:49	2020-12-12T10:05:49	graperoom.com	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-13T11:05:49.513	2020-09-13T10:05:49	2020-12-12T10:05:49	graperoom.com	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-13T11:05:49.513	2020-09-13T10:05:49	2020-12-12T10:05:49	graperoom.com	*.ecocool.co	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3