A breakdown of Apple’s Personal Knowledge Graph shows what your Mac and Apple Intelligence know about you and your life.

An example of contextual Siri on Mac
The upgrade to Siri AI added the understanding of personal context to Apple Intelligence. By pulling information from messages, emails, and photos, Siri can come up with answers to queries with contextual elements, such as knowing the name of your mother from a travel itinerary.
However, Apple has been compiling data on its users for a lot longer, with macOS 13 doing so since 2022. In a breakdown by security researchers at Eighth Rank, the generation of a Personal Knowledge Graph in macOS is detailed, including the kinds of data it compiles and retains on your Mac.