Debian is a free and open-source Linux distribution first released in 1993, serving as the foundation for hundreds of derivative distributions including Ubuntu, Linux Mint, and Raspberry Pi OS. As one of the oldest and most influential Linux distributions, Debian emphasizes stability, security, and community-driven development, making it ideal for servers, desktops, and embedded systems. Debian 13 "Trixie," released August 9, 2025, ships with Linux kernel 6.12 LTS, systemd 257, OpenSSH 10, Python 3.13, and PHP 8.4, while introducing the deb822 .sources format for APT repository configuration. Understanding Debian's three-branch system (stable/trixie, testing/forky, unstable/sid) is crucial — stable prioritizes reliability with thoroughly tested packages, while testing and unstable offer newer software at the cost of occasional breakage.
What This Cheat Sheet Covers
This topic spans 22 focused tables and 302 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
A jump-to index of every table row in this cheat sheet.
An interactive map of every table and concept in this topic.
Table 1: Package Management with APT
APT is the command you'll reach for daily — it's the high-level front-end that fetches, installs, upgrades, and removes software while resolving dependencies for you. The golden rule is to apt update before installing so you pull the newest available versions, and to know the difference between remove (keeps config files) and purge (wipes them). Trixie also adds conveniences like apt --update install and apt modernize-sources for the new deb822 repository format.
| Command | Example | Description |
|---|---|---|
sudo apt update | • Refreshes package list from repositories • run before installing or upgrading to get latest available versions | |
sudo apt upgrade | • Upgrades installed packages without removing existing packages • safe for routine updates | |
sudo apt full-upgrade | • Performs complete system upgrade, removing packages if necessary to resolve dependencies • required for major version upgrades | |
sudo apt install nginx | Installs specified package(s) along with all required dependencies | |
sudo apt --update install curl | • Refreshes package cache and installs in one command • replaces chaining apt update && apt install | |
sudo apt remove nginx | Removes package but keeps configuration files for potential reinstallation | |
sudo apt purge nginx | Completely removes package including all configuration files | |
sudo apt autoremove | Removes orphaned packages that were installed as dependencies but are no longer needed | |
sudo apt reinstall nginx | • Reinstalls package preserving existing configuration files • useful for repairing broken installations |