Definition of Terms

connection
  A connection is an object from the application's model. Connections link two other objects together, referred to as nodes. One node is referred to as the source, the other the target. In some applications, a connection may itself be a source or target node of another connection. GEF assumes that nodes know, or can obtain, the connections for which they are the source or target. The application does not need to have collection of all connections in it.
source connection
  An "outgoing" connection. The connection is leaving the object being talked about, making it the source of the connection.
source node
  The model object that is the source of a connection.
visuals
  Objects that are visible and rendered to the user in some way. Most EditParts have visuals which they manage. Examples include draw2d Figures and SWT TreeItems.