Detch:
1. Detach is used to disconnect a Business Object from an application
2. The Detach button has “disconnected” the Business Object from Order System and as a result, the Write stage no
longer works. Even though Order System is still there, the Business Object’s communication channel to the
application has been severed and the Business Object is no longer “aware” that Order System is running.
Attach:
1. Attach is used to connect a Business Object to a running application
2. Attach needs an input to help it identify the application
3. Attach will fail if the Business Object is already attached.
4. When a Business Object launches an application, it is attached automatically.
Read:
As the name suggests, the Read stage is the opposite of the Write stage; it is used to read data from application. A Write stage takes data （from the result of an expression） and puts it into an Application Modeler element, whereas the Read stage takes data from an element and stores them in a Data item.
Actions:
Business Object can only be used via a Process.
Business Object pages must be published before they are exposed for use
原文地址：https://www.cnblogs.com/taytaylovexiaoyu/p/8799327.html