The Business Object Layer implements all of the server's business functionality. As such, this layer contains the business application's "smarts". Within this layer, Business Process Objects (BPOs) represent the basic business entities modeled by the server application. BPOs implement the business logic of a Cúram server application. Typically these are responsible for manipulating Entity Objects in a business-specific way. This is where most of the development effort is (or should be) concentrated in business application development. For more information about BPOs, see Process Classes.