dpkg is the software at the base of the package management system in the free operating system Debian and its numerous derivatives. dpkg is used to install, remove, and provide information about .deb packages.
dpkg (Debian Package) itself is a low-level tool. APT (Advanced Package Tool), a higher-level tool, is more commonly used than dpkg as it can fetch packages from remote locations and deal with complex package relations, such as dependency resolution. Frontends for APT, like aptitude (ncurses) and synaptic (GTK), are used for their friendlier interfaces.
The Debian package "dpkg" provides the dpkg program, as well as several other programs necessary for run-time functioning of the packaging system, including dpkg-deb, dpkg-split, dpkg-query, dpkg-statoverride, dpkg-divert and dpkg-trigger. It also includes the programs such as update-alternatives and start-stop-daemon. The Debian package "dpkg-dev" includes the numerous build tools described below.