The Computers: Software: Operating Systems: (Mac OS Operating Systems )

The Mac OS is the original and still most popular operating system for the various versions of the Apple Macintosh computer, and Power PC. It was the first graphical window, menu, and icon based personal computer operating system, and had a strong influence on many other Operating Systems, such as the later Windows versions. Mac OS Operating Systems Software Computers.

macOS (originally named Mac OS X until 2012 and then OS X until 2016) is the current series of Unix-based graphical interface operating systems developed and marketed by Apple Inc. (wikipedia)