Diggers --
Data Analysis views provide totals information about Work and Cost for
projects, resources, and tasks. They also provide totals information from
WSS, such as the number of Risks, Issues, and Deliverables for each project
in WSS. They are most useful for executives, who need the "big picture"
view of what is happening with their organization's people and projects, but
can be viewed by PMs as well. That's a simple explanation.
By the way, since your questions seem to indicate that you are very new to
Project Server 2007, you might consider purchasing one or more of our
company's books on this subject at:
http://www.projectserverbooks.com
Our Managing Enterprise Projects... book is aimed at project managers, while
our Configuring and Administering... books is specifically for the Project
Server administrator. Hope this helps.