Debian, also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software and optionally non-free firmware or software developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of Debian (0.01) was released on September 15, 1993, and its first stable version (1.1) was released on June 17, 1996. The Debian Stable branch is the most popular edition for personal computers and servers. Debian is also the basis for many other distributions that have different purposes, like Proxmox for servers, Ubuntu or Linux Mint for desktops, Kali for penetration testing, and Pardus and Astra for government use.

A Linux distribution is an operating system made from a software collection that includes the Linux kernel and often a package management system. Linux users usually obtain their operating system by downloading one of the Linux distributions, which are available for a wide variety of systems ranging from embedded devices and personal computers to powerful supercomputers.