Linux is an open-source operating system based on the Linux kernel that was initially created for personal computers but is now widely used in servers, embedded systems, and smartphones through Android. Linux distributions contain the Linux kernel and supporting software and there are over 600 distributions available, some popular ones being Ubuntu, Debian, Fedora, and openSUSE. The core of the Linux architecture is the kernel which virtualizes hardware resources and prevents conflicts between processes, while system libraries implement OS functionality and shells provide an interface to the kernel.