Distribution:
http://en.wikipedia.org/wiki/Linux_distribution
In short - Linux is the kernel of the operating system, and a Linux distribution packages that kernel with a bunch of supporting routines and a package management system to keep everything in-check. There are hundreds of Linux distributions out there...Ubuntu, Mint, Debian, RedHat, SUSE, Slackware, LinuxFromScratch, Gentoo, etc.
In other words, are you using Ubuntu? Mint? Debian? What version?
Code:
sudo apt-get install-f
Is not a valid command. What did you try to install? What was your actual command? What was the output of running this command (that's what I mean by "output")?
Steam can be installed on most modern Linux distributions, but in some cases it can take some work. You need to work with us in order for us to be able to provide useful feedback and suggestions.
Did you install the operating system on this computer, or was it pre-installed? What kind of computer are we talking about here?