The DBEngine object is application independent. This means that the engine isn't specifically tied to any one host application. However, Microsoft Jet does provide a generic collection and object type so that an application can create and store its own objects in a database. This generic object is known as a container. The Containers collection holds all Container objects for a Database object.
As an example, Microsoft Access relies on Microsoft Jet to store its application-specific objects such as forms, reports, macros, and modules. Microsoft Jet keeps track of these foreign objects through the Containers collection. It's the Container object that enables Microsoft Jet to store application-specific objects without violating its application independence. You can use the Container object to set security to control access to all database objects of a particular type.