What is Linux?

Strictly speaking, Linux is the kernel of a computer operating system. A kernel is software that enables communications between computer applications and hardware, providing system services like file management, virtual memory, device I/O, and more. An Operating System needs more than just the kernel. The GNU organization ported, wrote and developed many of the software applications that combine with the Linux kernel to make a complete Operating System. This is why you will see the term GNU/Linux used when referring to Linux, to give credit for their contribution. Put all of this software together with some custom configuration and installation programs and you have what's referred to as a Distribution. Each distribution is created by a particular person or persons, be it a for-profit company like Redhat, or a group of like-minded individuals. Distributions vary in areas such as ease of installation, included software, and kernel versions.