Collections are containers that hold references to assets in the project. Since they are references, assets can be in multiple collections, and the collections they are in do not affect their location on disk. There are multiple types of Collections each with their own use and functionality.
Collections have a parent collection and can have child collections. By default the parent and children of a collection do not affect the assets that are in it, however a collection type may implement a functionality that does. (See: Compound Collection)
Every collection has settings which can be accessed either through the collection tree area context menu, or the gear icon on the right of every collection in the collections tree area.Settings are used to modify how a collection functions or is interacted with.
The “Update Items In Collection” button should be pressed after a collection’s settings have be changed to update the assets that are currently in the collection. This means different things for different collection types, but it could mean removing assets that don’t follow the new settings, or adding new assets.
Without doing this, new assets may be added to the collection following the new settings, while assets following the old settings may still be present even though they don’t follow the new settings. This could lead to confusion, but otherwise should not cause problems.
Updating the items in a collection in this way fully supports undo in case you change your mind or it was tone by mistake.
