Linux is a free Unix-type operating system originally created by Linus Torvalds with the assistance of developers around the world. Developed under the GNU General Public License , the source code for Linux is freely available to everyone 

 Linux is an operating system that was initially created as a hobby by a young student, Linus Torvalds, at the University of Helsinki in Finland. Linus had an interest in Minix, a small UNIX system, and decided to develop a system that exceeded the Minix standards. He began his work in 1991 when he released version 0.02 and worked steadily until 1994 when version 1.0 of the Linux Kernel was released. The kernel, at the heart of all Linux systems, is developed and released under the GNU General Public License and its source code is freely available to everyone. It is this kernel that forms the base around which a Linux operating system is developed.

Linux runs on a wide variety of hardware platforms, from huge mainframes to desktop PCs to cell phones. It is licensed under the Free Software Foundation's GNU Project's GNU General Public License, version 2, which lets users modify and redistribute the software.

                You can think of Linux as having two parts -- a kernel, which is the basic interface between the hardware and other system software, and the functions that run on top of it, such as a graphical user interface (GUI) and application programs.

  No single company sells Linux. Because it's open source software, anyone can package Linux with some programs and utilities and distribute it. The different "flavors" of Linux are called distributions.Linux is distributed by a lot of distributers all over the world.It is free and can get for free .It can be freely downloaded from authorised sites or it can be requested for getting via postage in internet.

 Useful links in which you can get linux are

                 http://www.linux.org/

                 http://www.linux.org/dist/download_info.html

                 http://www.getgnulinux.org/

                 http://www.linuxjournal.com/getlinux