2.2.6 Package priorities

Each Debian package is assigned a priority by the distribution maintainers, as an aid to the package management system. The priorities are:

• Required packages are necessary for the proper functioning of the system.

  This includes all tools that are necessary to repair system defects. You must not remove these packages or your system may become totally broken and you may not even be able to use dpkg to restore things. Systems with only the Required packages are probably inadequate for most purposes, but they do have enough functionality to allow the sysadmin to boot and install more software.

• Important packages should be found on any Unix-like system.

  Other packages without which the system will not run well or be usable will carry this priority. This does not include Emacs or X11 or TeX or any other large applications. These packages only constitute the bare infrastructure.

• Standard packages are standard on any Linux system, including a reasonably small but not too limited character-mode system.

  This is what will install by default if users do not select anything else. "Standard" does not include many large applications, but it does include Emacs (this is more a piece of infrastructure than an application) and a reasonable subset of TeX and LaTeX (if this turns out to be possible without X).

• Optional packages include all those that you might reasonably want to install even if you are unfamiliar with them, and if you don't have specialized requirements.

  This includes X11, a full TeX distribution, and lots of applications.

• Extra packages either conflict with others with higher priorities, have little use to users who are unfamiliar with them, or have specialized requirements that make them unsuitable for "Optional".

Please note the differences among "Priority: required", "Section: base" and "Essential: yes" in the package description. "Section: base" means that this package is installed before everything else on a new system. Most of the packages in "Section: base" have the "Priority: required" or at least "Priority: important", and many of them are tagged with "Essential: yes". "Essential: yes" means that this package requires to specify an extra force option to the package management system such as dpkg when removing from the system. For example, libc6, mawk, and makedev are "Priority: required" and "Section: base" but are not "Essential: yes".