Is Core Data Available on All Devices
Apple's persistence framework was introduced more than a decade ago so it's shouldn't surprise you that it is available on every platform, iOS, tvOS, macOS, iPadOS, watchOS, and Mac Catalyst.
The framework was introduced before you and I knew about Apple's plans to release iPhone. Apple made Core Data available to developers was alongside the release of Mac OS X Tiger in 2005. A few years later, the company made its persistence solution available on iOS with the release of iPhone SDK 3.0. The framework is currently available on iOS, tvOS, macOS, iPadOS, watchOS, and Mac Catalyst. It's wonderful to know that you can use the same persistence solution across Apple's platforms.
The only limitation you need to be mindful of relates to tvOS. You can use Core Data on tvOS, but you shouldn't use it for persisting data. Why is that? The documentation mentions that there is no persistent local storage for applications on tvOS. In practice, this mean that the data you write to disk can be purged at any time. While this won't happen at runtime, it can happen that the data you wrote to disk was deleted by the system the next time your application is launched. Keep that in mind.