For example, when you place a Document inside a Folder you are creating a small information sharing facility between the Document and the Folder. Because in Zope, the Document has access to all its container's content and services. So if a Folder can send mail, any Document placed inside the Folder can also send mail. Providing services Not only do objects acquire services, they also provide them. For example, adding a Mail Host object to a Folder provides that Folder with the ability to send mail.
Documents too can provide services to Folders.
In fact every object provides some service. So acquisition goes both ways, when you create an object in Zope it automatically acquires services, and it also automatically provides services that other objects can acquire. This makes reuse of services very easy since you don't have to do anything special to make services available to other objects. Getting Deeper with Multiple Levels OK, so if you place a Document in a Folder, it acquires the Folder's behaviors. So what happens if things get more complex.