The new wave of web applications are built on technologies such as AJAX and Microsoft Silverlight that enable developers to build better, richer user experiences. These technologies bring a shift in how applications are organized, including a stronger separation of presentation from data.
ADO.NET Data Services (also known as Project code name “Astoria”) consists of a combination of patterns and libraries that enables any data store to be exposed as a flexible data service, naturally integrating with the Web, that can be consumed by Web clients within a corporate network or across the Internet. ADO.NET Data Services uses URIs to point to pieces of data and simple, well-known formats to represent that data, such as JSON and ATOM/APP. This results in data being exposed to Web clients as a REST-style resource collection, addressable with URIs that agents can interact with using standard HTTP verbs such as GET, POST, or DELETE.
For the system to understand and leverage semantics over the data that is surfacing, ADO.NET Data Services models the data exposed through the data service using a model called the Entity Data Model (EDM), an Entity-Relationship derivative. This organizes the data in the form of instances of "entity types", or "entities", and the associations between them.
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