An operating system created series by Apple Inc. since 2002.

Previously Mac OS X and OS X, macOS is a series of Unix-based graphical interface operating systems developed, marketed, and sold by Apple Inc. It is designed to run exclusively on Mac computers, having been pre-loaded on all Macs since 2002. Releases of macOS were first named after big cats, then after places in California: for example, OS X v10.8 is referred to as "Mountain Lion", and macOS v10.14 is "Mojave".