What is dpkg used for in Linux?

dpkg is a tool to install, build, remove and manage Debian packages. The primary and more user-friendly front-end for dpkg is aptitude(1). dpkg itself is controlled entirely via command line parameters, which consist of exactly one action and zero or more options.

What is dpkg and apt?

APT vs dpkg: Two Important Package Installers. APT and dpkg are both command-line package management interfaces you can use in the terminal on Ubuntu and other Debian-based systems. They can, among other things, install DEB files and list installed packages.