Generally, the application data only contains information that is meaningful to the applications, since the controlinformation in the message descriptor is sufficient.
一般地，应用程序数据仅包含对应用程序有意义的信息，因为消息描述符中的控制信息就已经足够了。
2
It identifies the message and contains controlinformation, such as the type of message and its priority as assigned by the sending application.
它标识消息且包含控制信息，比如消息类型和由发送应用程序分配的优先级。
3
The header is used to pass controlinformation, and the body contains the actual request or response message content.