Accessing Data Using REST
REST, also referred to as ADO.NET Data Services, offers additional methods for accessing and querying SharePoint list data down to list item level. Additionally, if you are using SharePoint Server 2010 then you can also use REST to access cells in published Excel services workbooks. SharePoint exposes a number of REST Web services, located on the Web front-end server, and denoted by the suffix .SVC. Similar to the SOAP service connection, the REST service connection offers another means by which to access list data from other sites within site collections.
In order to access and work with REST, your SharePoint Web front-end server needs to have the ADO.NET Data Services Update for .NET Framework 3.5 SP1 for Windows ...