Linux is an Operating System. Ma-Bell made UNIX Operating System, Microsoft makes Windows Operating System, & Apple Mac makes MacOS Operating System, but the Whole World helps to make Linux. The creation of Linux came about from a need to use UNIX, but, not beeing able to afford a licence to legally use UNIX. So, a man named Linus Torvalds and others remade the core (the kernel). Now we have Linux, & you can install it & use it for free instead of Microsoft Windows if you wish.