Editing basics for the xorg.conf file
For many users, the xorg.conf file, which configures the system resources, graphics card, keyboard, pointing device, and monitor for a computer running the X Window System, is an exception to GNU/Linux's do-it-yourself credo. Users who think nothing of editing /etc/fstab or /etc/hosts.allow will shy away from xorg.conf for fear of breaking their systems, relying instead on tools such as the KDE Control Center or Debian's dpkg-reconfigure xserver-xorg instead. But learning your way around xorg.conf not only teaches you a lot about how your system operates -- it can also come in handy when the graphical display fails and you either can't remember the handy command that does the work for you, or you're working with a distribution that isn't blessed with it.
It's easy to understand users' caution. Not only does xorg.conf contain a lot that can go wrong, but it is only fitfully documented in man and Web pages. Moreover, because the file's settings are specific to each system, borrowing an example of the file off the Internet is unlikely to give you more than basic ideas of how to get its settings correct. However, so long as you remember to make a backup copy of the file and keep within the settings defined by the documentation that comes with the hardware, the danger is actually minimal.
The xorg.conf file is divided into a minimum of eight sections.