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

Results forwww.dev.graphdbs.io

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-01-05T15:24:21.607	2020-01-05T14:24:21	2020-04-04T14:24:21	graphdbs.io	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-05T15:24:21.44	2020-01-05T14:24:21	2020-04-04T14:24:21	graphdbs.io	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-30T06:14:34.794	2019-09-30T05:14:34	2019-12-29T05:14:34	bandwallet.bandprotocol.com	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-30T06:14:34.396	2019-09-30T05:14:34	2019-12-29T05:14:34	bandwallet.bandprotocol.com	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-30T04:30:54.166	2019-09-30T03:30:53	2019-12-29T03:30:53	www.dev.graphdbs.io	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-30T04:30:53.882	2019-09-30T03:30:53	2019-12-29T03:30:53	www.dev.graphdbs.io	www.dev.graphdbs.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3