Data access is crucial in most applications. The architecture of Ext JS and Ext.NET's data access allows for a lot of flexibility. We looked at XTemplates that allow rich formatting of repeated data, and DataViews and ComboBoxes as examples where XTemplates are used. We also looked at Stores and Models, introduced with DataViews and ComboBoxes, which showed us how data-driven applications are modeled and how the architecture supports a clean separation of concerns.
Ext.NET is vast and would require volumes to write about all of its features! For example, a powerful new feature in Models is the ability to relate data to each other, much like how tables in a relational database can be related or how your data may be hierarchical. For example, a Person object may have a complex Address object. Ext.NET supports modeling data using Associations. It is worth studying some useful examples in the Ext.NET Examples Explorer at http://examples.ext.net/#/search/associations.
There are many other...