package encapsulation (BC-DWB-TOO-PAK)

Unlike non-encapsulated packages (white box), encapsulated packages hidetheir contents from external access (black box). As a result, repositoryobjects of a package can only be used if they have been exposed on a package interface of a server package, making them visible externally. Package encapsulation can have different attributes, however. The scope of encapsulation is defined using three encapsulation levels.The possible uses of a repository object, on the other hand, are definedand specified by means of the usage types permitted on a package interface.