Moderators help keeping Pregly a nice place. They are not police officers, but help out members with their queries and they keep threads alive by asking questions. Of course they are allowed to delete or close inappropriate threads, this is part of their role. However, this is not their primary role.
You can read their guidelines, yes - they have them :-), and what resources they have available here:
If you are interested in becoming a moderator yourself, have a look at the page which tells you a bit about the process involved.