PI Web Services provides SOAP-based access to PI System data. This can be very useful for visualization and integration with business systems through web queries. Please see this page for general product definitions and user manuals. Also, there are a few training videos in vCampus Training Center (under Data Access on the right hand side of the page). In the same Training Center, there is material for PI Application Development course that details working with PI Web Services, among other things. And finally, there are vCampus discussion forums at your services for your questions.