MacOS
/ˌmæk-ō-ˈɛs/
n. “A polished surface over a deeply UNIX mind.”
macOS is Apple’s desktop operating system, designed to sit at the intersection of consumer friendliness and serious computing. It presents itself as smooth, quiet, and visually restrained — but beneath that calm exterior lives a full UNIX-based operating system capable of doing real work, real damage, and real engineering.