The release is defined by the mandatory integration of "Apple Intelligence," a suite of generative AI features that can no longer be toggled off to save disk space.
The update matters because it significantly increases hardware requirements and storage consumption.
While all supported Macs can run basic AI models, a more powerful "AFM 3 Core Advanced" model—which enables more expressive Siri voices and better dictation—specifically requires an M3 chip or newer and at least 12GB of RAM.
For users on older machines, the mandatory AI models can consume between 14GB and 22GB of storage, a concrete consequence for those using entry-level devices during a period of high costs for memory and storage upgrades.
Beyond AI, Golden Gate introduces "Liquid Glass," a refined visual design that addresses several criticisms of the previous version by adding a transparency slider and consistent window corners.
Useful productivity changes include Markdown support in the Notes app, native 5K ultrawide monitor support, and "iPhone Mirroring," which now allows users to resize phone app windows on their desktops.
Additionally, Apple has signaled the upcoming end of Rosetta 2—the software that allows Intel-based apps to run on new chips—by adding system warnings that such apps will stop working in the next major macOS release.