1.4 Relationship to Protocols and Other Structures
The DiffGram structure is used by the ADO.NET Framework as a serialization format for the contents of DataSets. Whenever a DataSet is returned from or received by a web service method, the DiffGram structure is used as the default serialization format. When used this way, the DiffGram can be wrapped in other data structures (for example, as specified in [SOAP1.1], Section 4) that encapsulate other parts of the web service call.
The services that exchange DataSets can use a variety of network protocols and encodings to transfer DiffGrams. For example, one web service can choose to use a plain-text encoding of a DiffGram within a Simple Object Access Protocol (SOAP) envelope, transmitted using Hypertext Transfer Protocol (HTTP) as specified in [RFC2616]. Another can choose a binary encoding for the SOAP envelope containing the DiffGram and transmit it via User Datagram Protocol (UDP). The network protocols and encodings that can be used to transmit DiffGrams are not covered in this document.