There are three kinds of sessions.

* user sessions are the most common: they are related to users and

  carry security checks coming with user credentials

* super sessions are children of ordinary user sessions and allow to

  bypass security checks (they are created by calling unsafe_execute

  on a user session); this is often convenient in hooks which may

  touch data that is not directly updatable by users

* internal sessions have all the powers; they are also used in only a

  few situations where you don't already have an adequate session at

  hand, like: user authentication, data synchronisation in

  multi-source contexts

Do not confuse the session type with their connection mode, for

instance : 'in memory' or 'pyro'.