A connection is an object that binds together two ports. It establishes a relationship between two symbols through the two ports it connects. Think of connection objects as the glue that connects two ports. A port can have more than one connection on it, but a connection can only be associated with two ports.
The term dependent is used to refer to the port and symbol pair on the other side of a given connection. In other words, the dependent ports for a given symbol are ports on other symbols that the given symbol has connections to. If symbol A is connected to symbol B, then symbol B is a dependent of A, and symbol A is a dependent of B. In other words, they are co-dependent.
Connections are used to send event notifications to dependent symbols. For example, if symbol A is connected to symbol B and symbol A moves, then symbol A must notify symbol B of the change so that B can take appropriate action. Links respond to this type of notification by following the symbol to which they are connected. If symbol A is connected to link B, and symbol A is moved, then link B is notified of the move and responds to this notification event by adjusting its endpoint to follow symbol A.
Figure 85 – Connection Class Hierarchy