LINUX

Linux is a relatively new operating system that clones the UNIX operating system. It was written by Linus Torvalds and a scattered team of volunteer programmers across the Internet. The Linux kernel and many system components are released under the GNU General Public License (GPL), which dictates that the source code for those components, including modifications, must be made available under the the GPL or a compatible license whenever a compiled version is distributed.
An operating system (OS) is a special program that acts as an intermediary between the computer user and the computer hardware. Apple's MacOS and Microsoft Windows are operating systems. The OS provides an environment to make the computer system convenient and efficient to use. Among other things, the operating system delegates which program should run, manages memory, provides a file system interface, schedules hard disk access, manages the network (e.g. TCP/IP), allows programs to talk to one another, and provides security.