Universally Unique Identifier (UUID)
A UUID (Universal Unique Identifier) is a 128-bit number used to uniquely identify an object or entity in a system.
In the GDC every entity in the data model is assigned a UUID. An entity can be a file, case, project, or other node. Uniquely identifying objects in this manner allows the GDC to have a uniform method of referencing any object in the system1.