Debian is known for its adherence to the Unix and free software philosophies, and for its abundance of options — the current release includes over fifteen thousand software packages for eleven computer architectures, ranging from the ARM architecture commonly found in embedded systems to the more common Intel x86 and AMD x86-64 architectures found in modern personal computers.

Debian is also known for its package management system (especially APT), for its strict policies regarding the quality of its packages and releases, and for its open development and testing process. These practices afford easy upgrades between releases without rebooting and easy automated installation and removal of packages.