A container is a helper object that lets you organize scene contents into logical groups that can then be handled as a single object. Because a container and its contents can be saved as a MAXC file, it can be shared among multiple users.
Contents of each city block is grouped in its own container
Containers are designed to:
A container that is created locally and used to organize scenes is referred to as a Unique Container. Its content is not inherited from an external source.
A source container inherits content from an external source. The source content can be updated each time the container;s siyrce definition is saved. A source container can be edited if access is granted by its author.