Windchill Fundamentals > Working with Windchill Objects > Managed Collections
Managed Collections
A managed collection is an organized set of objects that are managed as a cohesive group. A managed collection differs from a baseline. A baseline is essentially a snapshot of a group of objects and cannot be updated. A managed collection retains the knowledge of the initially selected objects and collection options so it can be refreshed to allow its membership to evolve based on the collection options.
Managed collection contents are based on initially selected objects and various collection options. After adding initially selected objects to or removing them from the managed collection, you can configure collection rules to determine the managed collection contents based on the set of initially selected objects. Managed collections can be used to gather related objects into a cohesive set for inclusion in a package that has complex collection requirements or a variety of objects.
Managed collections can be nested and thus provide a hierarchical structure of collections. A single managed collection can be reused in one or more packages or other managed collections. Grouping one or more managed collections allows you to gather information with different initially selected objects and collection rules, allowing for increasingly complex collection options.