CompleteProject is very dependent on project hierarchies.  The project hierarchies allow the application to manage security permissions in a very elegant and easy to understand way. The hierarchies do cause a problem however in that it can be difficult to know when a subproject has been modified without navigating through the entire hierarchy.
That's where the activity views come in - we can use the activity tab to see what is going on in all of our projects at the same time without having to navigate to each individual project and subproject.  In that sense the activity tab provides us with summary information on all of our projects.

Activity Toobar

1. Activity Toobar
The activity toolbar is used to navigate through the various activity views. Selecting items from the toolbar is the same as selecting items from the activity view list. For more information please see the activity toolbardocumentation.

Activity Views

2. Activity Views
The activity views box can be used to select an activity view. Note that the views listed in the activity views box are the same as those listed in the activity toolbar. For more information see the activity views documentation.

Activity Data

The activity data section show information which is relevant to the selected activity view.  The information displayed in the activity data section will change based on the view selected.