A version of the Linux operating system and related components. A Linux distribution includes the Linux kernel, software modules from the GNU Project, an installation program, window manager (user interface), utilities, applications and documentation. Some distributions contain a thousand or more files. See GNU/Linux.Linux distributors may offer both free and paid versions, whereby the free version comprises an older kernel, fewer utilities and support only via online documentation and forums. For example, Red Hat's Fedora is free but without support (see Fedora). Paid versions include the latest modifications and software with a full tech support program.Why Is It Called a Distribution?A Linux distribution, and there are hundreds of them, is not like the next version of Windows and macOS. Each Linux "distro" is a current version that has components that may differ slightly or greatly from another Linux distribution. For the most popular ranked by hits per day, visit www.distrowatch.com. See Linux, GNU, GNU/Linux, arch, embedded Linux and open source.