Mac OS 9 is the ninth and final major release of Apple’s classic Mac OS operating system, which was succeeded by Mac OS X 10.0 in 2001, starting the Mac OS X family of operating systems. Introduced on October 23, 1999, it was promoted by Apple as “The Best Internet Operating System Ever”…
Source: Wikipedia
What is an operating system?
An operating system is the most important software that runs on a computer. It manages the computer’s memory and processes, as well as all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer’s language. Without an operating system, a computer is useless.
Source: GCFGlobal
NOTE: Mobile devices such as smartwatches, tablets & smartphones also have operating systems.
