There is more than one way to install a Gnu/Linux distro into a PC/laptop. Gnu/Linux can be installed in various ways to a hard disk -- using a CD/DVD, from network, through flash drives, etc. Almost every six months new and improved version of distro are released. Be it Canonical's Ubuntu or Redhat's Fedora, we find a stable distro released every six months and quite a number of alpha and beta version being released before the stable release.