The Macintosh Operating System (Mac OS) is an operating system created by Apple to be installed and operated on the Macintosh series of computers. The system was implanted in 1984 as a graphical user interface.
Since then there has been multiple different versions, released to both keep it updated and also squash any bugs they may have obtained. MacOS is widely considered the pioneer of operating systems as it was released when the competition was in comparison, very basic.
The system is designed to operate on apple computers and therefore does not support competing products.