Debian GNU/Linux is probably the only Linux distro that has the largest software repository. However the default installation for Debian only includes the ‘main’ repository which is directly maintained by the Debian community and fulfills the Debian Free Software Guidelines (DFSG).
The two other repositories ‘contrib’ and ‘non-free’ are not enabled by default as it contains software that either does not meet DFSG requirements or depends on library or packages which does not meet DFSG requiments.
How to enable contrib and non-free repo in Debian
As ‘root’ you need to edit /etc/apt/sources.lst
Then add ‘contrib’ and ‘non free’ at the end of each line that begins with “deb” and “deb-src” just like the example:
deb http://http.us.debian.org/debian jessie main contrib non-free deb http://security.debian.org jessie/updates main contrib non-free
Save the file, and run ‘apt-get update‘ and optionally ‘apt-get upgrade‘ to activate the changes.