考虑一个三层应用程序，一部份程序以智能客户端的形式在运行，而另一部份则是在服务器上运行。

Consider a three-tiered application, in which part of the application runs as a smart client and part of the application runs on the server.

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另一个例子是用于Web服务，这些服务支持与客户端之间进行某些形式的会话。

Another example is for Web services that support some form of session with a client.

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本例中的客户端可以是应用程序代码或系统代码的某一形式。

The client in this case can be either application code or some form of system code.

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