Terminology

Asset - A source file on disk, typically located in the Project’s Assets folder. This file is imported to a game-ready representation of your Asset internally which can contain multiple Objects (SubAssets.)

Object (SubAsset) - A single Unity serializable unit. Also known as a SubAsset. An imported Asset is made up of one or more Objects.

Includes - The unique set of Objects from which an Asset is constructed.

References - The unique set of Objects that are needed (referenced) by the Includes of an Asset, but not included in the Asset.