"The Advanced Packaging Tool (APT) is a distinguishing feature
of Debian-based systems. APT was the first major alternative in
GNU/Linux to boast automatic dependency resolution. Most GNU/Linux
users know it through the apt-get command, a utility that calls on
the lower-level dpkg command. However, other APT-based utilities
remain largely unknown to desktop users. Some of these utilities
offer a range of functionality far beyond those of the basic
tools.
"These functions include setting up package sources (apt-cdrom
and apt-spy), querying package information (apt-cache and
apt-rdepends), extracting the latest list of bugs associated with a
package (apt-listbugs), and receiving automatic updates
(apt-watch). Many can be run from any account; you need the root
account only for the final stages of configuration or the
installation and removal of packages..."