·         Workflow services, new for 3.5, are services that are authored using workflows. Durable services are services that use a persistence provider to persist state information after an operation has completed.
·          The implementation of the service contract is handled through one or more ReceiveActivity activities, which are sequence activities that support either one-way or request/response message exchanges with a client. The client invokes operations through SendActivity activities, which are basic activities that support the same message exchange scenarios as the workflow service.
Workflow Services Samples
·         Calculator Client Sample - the client application that is used with the calculator state machine service.
·         Durable Service Sample - implement a basic calculator as a durable service.
·         Sequential Workflow Service Sample - create a workflow service by using a sequential workflow & create a service contract in place.
·         State Machine Workflow Service Sample - Demonstrates how to create a workflow service by using a state machine workflow. implement a basic calculator by using a state machine workflow.
·         Workflow First and Security Sample - Demonstrates the "workflow first" method of authoring services as well as security features within workflow services.
·         Conversations Sample - Demonstrates how a workflow service can have parallel conversations with multiple clients over the same contract.
·         Duplex Workflow Service Sample - Demonstrates how to perform asynchronous duplex communication between two communicating services. Also demonstrates how to perform localhost-to-workflow communication by using messages.
·         Workflow Service Utilities - Contains all the utilities that the other samples in this section use to manipulate the context and create the listener infrastructure for local services.