iTunes, the unified account by which Apple apps and services are accessed on devices such as Macs, seems to have been around forever. However, it also appears that this is no longer the case. A 9to5Mac contributor has confirmed rumors that the new protocol Marzipan is being used to make new apps (e.g. Apple TV) that do not require this old system on macOS.
https://www.notebookcheck.net/Apple-to-phase-iTunes-out-in-favor-of-standalone-media-apps-in-future-versions-of-macOS.416222.0.html