What you are installing on your computer is called a Linux distribution, or a Linux-based operating system. A Linux distribution takes all the parts mentioned above and assembles them, eventually polishing and customizing them. There are hundreds of good Linux distributions out there, and I couldn't contain all of them here. Some examples include the popular Ubuntu , Debian , openS USE or Fedora . You can find more information about Linux distributions at DistroWatch or on Wikipedia. In this tutorial we will focus on Bash, since it is the most widely used and also one of the most powerful shells out there. Bash is a modern implementation of the older Bourne Shell (sh), developed by the GNU project, which provides a huge amount of tools and which, together with the Linux kernel, desktop environments like GNOME or KDE and applications which run on top of them, comprise the whole Linux platform. On a Debian or Ubuntu distribution, the default shell used by the system is specified in the file /etc/passwd (default being Bash).