Read the original post at Windows Phone 7 Developer Guide
Microsoft provides a range of technologies for exposing data in standard formats. Typically, on the Windows platform, you will expose data through a SOAP-based or a REST-based service; using a technology such as Windows Communication Foundation (WCF) to implement SOAP-based services or a framework such as WCF Data Services for REST-based services. Frameworks such as WCF Data Services and WCF RIA (Rich Internet Application) Services can expose data in the OData, Atom, Atom Pub, and JSON formats, and support a full REST-based service interface for updating, deleting, and adding new data to the server-based store. Other server frameworks for Windows and other platforms can do the same.