6.7 What is an Essential Required, Important, Standard, Optional, or Extra package?
Each Debian package is assigned a priority by the distribution
maintainers, as an aid to the package management system. The priorities are:
Required: packages that 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
probably not even be able to use dpkg to put things back. Systems with only
the Required packages are probably unusable, but they do have enough
functionality to allow the sysadmin to boot and install more software.
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. It
does not include many large applications, but it does include some development
software like the GNU C and C++ compilers (gcc, g++),
GNU make, as well as the Python interpreter and some server software like
OpenSSH, the BSD printer daemon (lpr) and the RPC portmapper
Extra: packages that either conflict with others with higher
priorities, are only likely to be useful if you already know what they are, or
have specialized requirements that make them unsuitable for
If you do a default Debian installation all the packages of priority
Standard or higher will be installed in your system. If you
select pre-defined tasks you will get lower priority packages too.
Additionally, some packages are marked as Essential since they
are absolutely necessary for the proper functioning of the system. The package
management tools will refuse to remove these.