One of the tools used to install packages on a &debian; system is a program called apt-get, from the apt package Note that the program which actually installs the packages is called dpkg. However, this program is more of a low-level tool. apt-get is a higher-level tool, which will invoke dpkg as appropriate. It knows how to retrieve packages from your CD, the network, or wherever. It is also able to automatically install other packages which are required to make the package you're trying to install work correctly. . Other front-ends for package management, like aptitude and synaptic, are also in use. These front-ends are recommended for new users, since they integrate some additional features (package searching and status checks) in a nice user interface. In fact, aptitude is now the recommended utility for package management. apt must be configured so that it knows where to retrieve packages from. The installer largely takes care of this automatically based on what it knows about your installation medium. The results of this configuration are written to the file /etc/apt/sources.list, and you can examine and edit it to your liking after the install is complete.