There are an ever growing/evolving number of Identifiers used within the music industry to help identify entities and entries alike!
In our system, we have the likes of:
ISRC (Assets)
ISWC (Works/Assets)
IPI/CAE (Contacts/Composers/Publishers)
ISNI (Contacts)
IPN (Contacts)
You can read more about these Identifiers - what they are, where they are assigned from and more in this article form MLC: https://www.themlc.com/identifiers