installing_packages

APT commands
What is apt?
  Advanced Package Tool.

Wiki :-
	The Advanced Package Tool, or APT, is a free software user interface that works with core libraries 
	to handle the installation and removal of software on the Debian, Slackware and other Linux distributions. 
	APT simplifies the process of managing software on Unix-like computer systems by automating the retrieval,
	configuration and installation of software packages, either from precompiled files or by compiling source code.

--- Install a package ---
sudo apt-get install <package_name>

deb packages
Packages are manually installed via the dpkg command (Debian Package Management System). 
dpkg is the backend to commands like apt-get and aptitude, which in turn are the backend for 
GUI install apps like the Software Center and Synaptic.

Something along the lines of:

dpkg --> apt-get, aptitude --> Synaptic, Software Center

Install a package
sudo dpkg -i DEB_PACKAGE

Remove a package
sudo dpkg -r PACKAGE_NAME