This demo is designed to show you a Hierarchy data view. Several types of data is best represented by a hierarchy. In some cases with small amounts of data; you will want to download the entire hierarchy to the client. In most cases though; you would prefer that only the data that needs to be sent is sent.
You will notice with this demo that each user has different data available. This data can be driven by a database (like in this example) or hard-coded. Also the "Admin" user has both user's data available.