macOS Monterey (version 12) is the eighteenth release of macOS, shipped on October 25, 2021, alongside the M1 Pro/Max MacBook Pros. Its star was Universal Control: one Mac's keyboard and trackpad flowing seamlessly across neighboring Macs and iPads — files dragging between devices — ecosystem magic that reviewers called the demo of the year (it shipped in 12.3, fashionably late).

AirPlay to Mac made the desktop a receiver, Shortcuts crossed from iOS to begin Automator's succession, Focus modes synced across devices, and Safari weathered a beta-long argument about its compact tab design before shipping with the old layout available.

Universal Control (12.3); AirPlay to Mac; Shortcuts; Focus; FaceTime's SharePlay, links, and grid view; Live Text; Quick Note; Low Power Mode on Mac; and iCloud+ Private Relay. Intel Macs sat out a few features (portrait-mode FaceTime, Maps' 3D cities) — the silicon gap's first visible seams.

Universal Control remains the ecosystem's showpiece, and Monterey's feature gating previewed the two-tier Intel/Apple-silicon reality of the transition years. Shortcuts' arrival set desktop automation's future path.