The Debian package management infrastructure is a simple yet powerful system that has been a distinguishing feature of Debian since the project's early years. At the core of the Debian package management is dpkg [1], a low-level tool used for installing and removing Debian .deb packages. The bigger and more comprehensive Advanced Package Tool (APT) [2] is a higher-level tool that includes dpkg on the back end. APT performs most of the other functions associated with a package management system, including integrating external repositories.

The APT package system supports a number of front-end applications, both command-line and GUI-based, that act as a user-friendly interface for managing Debian packages. In the past, most users who wanted to work at the command line depended on the classic apt-get tool as an interface to the Debian package system. Through the years, apt-get and a constellation of other supporting utilities, such as apt-cache, have provided nearly effortless package management for Debian users, as well as users of Debian-based distros like Ubuntu and Knoppix, who take the time to master the commands.

However, some users were not happy about the complex, and often confusing, system of apt-get commands and options. Since the release of Debian 8 "Jessie" and Ubuntu 16.04 "Xenial Xerus," all users of Debian-based systems can enjoy a new command-line interface to the APT system: apt. The apt utility consolidates features that were once spread among apt-get, apt-cache, and other commands, and it simplifies many of the command options for an easier and friendlier user experience.

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