Just as Graphical User Interfaces (GUI) dominates in Windows, likewise most people with a Linux PC do all of their work without ever using a command line. While the knowledge to work on a command is certainly very valuable for complete administrative control over the system, it's not absolutely required for most operations under Linux today. If most people would stop to think about it, the average Windows user doesn't know how to fix things when they go wrong either- as they often do. If you choose one of the well-known distros such as Fedora, Ubuntu, or openSUSE, you'll probably be surprised to see self-explanatory, colorful icons just as you do under Windows. What's more is that, unlike Windows, you can safely experience the Linux desktop without ever installing the system by taking advantage of what are known as live Compact Discs (CDs). You simply place the CD in the tray and reboot. A very simple menu offering you some choices such as the option to run the CD live or to install will appear so that you know exactly what's about to take place before things start running.