CurrentUser Query

Hello all!
I am trying to use the current user query in order to exploit it in my application. My question is:
Which user does the api return?
Is it the user logged in the operate platform for example?

I am using a self managed implementation and inside keycloak I have created two users with names and all.

After performing the query I get a response like:

        "userId": "5c829631-db2d-48f7-a7eb-46fef4c29e99",
        "displayName": "5c829631-db2d-48f7-a7eb-46fef4c29e99",

And after trying to logout and login with the second user I get the same response. So probably, the api refers to a different user?
Thank you!