Explain observable to me

It seems like you're interested in understanding the concept of "observable." While the context provided doesn't directly mention observables, I can relate it to the concept of tracking and event handling in the context of Apple's WWDC sessions.

In the session titled "Explore object tracking for visionOS," the concept of tracking real-world objects and using them as virtual anchors is discussed. This involves using object tracking technology to create immersive experiences by anchoring virtual content to real-world items. This is somewhat analogous to the idea of observables in programming, where you observe changes or events and react to them.

For example, in the session "Discover media performance metrics in AVFoundation," the concept of subscribing to events is explored. Here, you can subscribe to various media performance metrics events, which is similar to observing changes or events in a system and reacting to them.

If you are interested in a specific session or topic related to observables, please let me know, and I can provide more detailed information or timestamps from the sessions.