Dpkg

dpkg is the Debian package manager. It is a medium-level package management tool that extracts and configures .deb packages, however it does not download packages or automatically resolve dependencies.

APT is a higher level package management system that automatically downloads packages and resolves dependencies.

Installation
To install a .deb package, use  or its shorter form. dpkg -i .deb

This must be executed as root. You can use sudo: sudo dpkg -i .deb

Removal
There are two types of removal that can be done:
 * Normal removal - this removes the package's files but leaves configuration files in place.
 * Purging - this removes all the files including the configuration files.

To remove normally, use  or. dpkg -r  NB: Use the package name, e.g. 'firefox', instead of                              its filename.

To purge, use  or   (with a capital). dpkg -P