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

Results forcool.weeklytraining.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2022-11-24T00:34:18.581	2022-11-23T23:34:18	2023-02-21T23:34:17	arbitrage.exchange	soft.cool.weeklytraining.com	C=US, O=Let's Encrypt, CN=R3
2022-11-24T00:34:18.308	2022-11-23T23:34:18	2023-02-21T23:34:17	arbitrage.exchange	soft.cool.weeklytraining.com	C=US, O=Let's Encrypt, CN=R3
2022-01-19T07:44:45.737	2022-01-19T06:44:45	2022-04-19T06:44:44	district158parentsunion.org	eyes.cool.weeklytraining.com	C=US, O=Let's Encrypt, CN=R3
2022-01-19T07:44:45.498	2022-01-19T06:44:45	2022-04-19T06:44:44	district158parentsunion.org	eyes.cool.weeklytraining.com	C=US, O=Let's Encrypt, CN=R3