The objects and dependencies seen in this window represent the call and data dependencies between the functions and data structures in the subject program. An arc from the bottom of an object to the top of another object means that the first object depends on the second. In this window (if you are using the default colors), green objects represent functions and yellow objects represent data structures. A yellow arc between a function and data structure implies that the function accesses the internal structure of the datatype. A purple arc between two functions indicates that the first function calls the second function. Note that the overview window does not contain any of the dependencies between the nodes within a level. This is because the overview is designed to show the overall decomposition of the software system and not the system in its entirety. On the other hand, the window that contains the source code level does not display any dependencies to objects outside of that window. Each type of window is designed to display a specific type of information