Introduction to Microsoft Windows Workflow Foundation (1)

The younger brother hasn't made any contribution to the garden since he spent so long in the blog garden. I am so ashamed to see something about the workflow on msdn today. I want to translate it and exercise my skills in English.
Although the younger brother is not good at English, give it a try.
If you want to see the original English, msdn address: http://msdn2.microsoft.com/en-us/library/aa480215.aspx

Windows Workflow Foundation description:
In fact, today's enterprise application software has a common goal: to support business process processing. Use differentProgramAnd some business processes are automated. Most of the problems that often come out may be solved by manually starting a process and reviewing the document. On the other hand, we can define a series of separation processes as a workflow to describe some activities of the business processes that people and software need to solve. 1. After completing the definition of a workflow, the program can execute the business process based on it.
Creating and executing a workflow brings you a new challenge. Some business processes may take hours, days, or even weeks to complete. As a developer, how can we maintain the current state of the workflow within such a long period of time? This type of long-running workflow may also communicate with other programs without a wall plug. How can developers easily implement asynchronous communication.