What is the difference between the Data Provider for Joomla and the Data Provider Framework?

The pj DataProvider Framework is a core library independent of the (PHP) environment. This is where the DB interface functionality takes place.

The pj DataProvider for Joomla! library intermediates this functionality to clients under Joomla! CMS. It opens the Framework with actual Joomla! settings, passes client calls to it and adds some Joomla! specific functions and classes.