An asset can be added to one or multiple collections.
How to add assets to a collection
- Drag over or select one/many assets in view of the Asset pane thumbnail views you wish to add and build up your collection with
- Right-click the assets, select Add to collection, then choose the collection from the list. You can also drag assets onto a collection in the Collections & Productions panel.

- The asset(s) have been added to the collection.
Related: Create a collection, Remove assets from a collection and Reordering items in a collection.