How to see profile assigned to a user

In order to find out the users and the profile assigned you can use the commands below.

DESC DBA_USERS; 

This will show you all the fields name for which you want to query

SELECT USERNAME, PROFILE, ACCOUNT_STATUS FROM DBA_USERS; 

And this command will show you the user name, profile and account status i.e. which profile is assigned to which user

You can find this information in dba_users.profile view: http://docs.oracle.com/cd/E18283_01/server.112/e17110/statviews_5081.htm