A trading partner connection is the combination of a document sent or received from a given trading partner.  For example, an 810 Out to Walmart is one trading partner connection.  An additional 810 Out to Lowes would make it two trading partner connection....

The Lite version is used for any Grey Wolf application (like Altitude, Partner Connect, etc).  The Full version is used for applications that are third party or custom in-house applications.   Basically, you will need the Full Version for anything but Grey Wolf applications....

Partner Connect integrates with your ERP thru the Grey Wolf Connector.  You will need the Lite version of the Connector....

Altitude provides real-time information from your ERP.  The Grey Wolf Connector will provide that integration and is required....

Keystone uses Grey Wolf's Connectors to integration with ERPs.  If you need to connect to your ERP, you will need the associated Connector....