OK
1. Is there a user guide for ES? I cannot seem to find it
2. What is the 'password' category showing me. I have other specific categories that make sense; user, employee etc. What is password?
Http://docs.splunk.com/Documentation/ES
Tough to guess the context that you have in mind, where are you looking?
Edit: saw from the title that you're in Identity Center... I think that there is no stock "password" category. Category is a free form field that you can populate with anything. There are some strings that we look for like "email" or "vulnerability", I don't recall password being one of them though.