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UDEV and the driver manager, the UDEV system, means many device files, can be dynamically created whenever appropriate hardware is detected, whether it be during the boot process or with hot plug hardware. For example, when I attach a USB key to my Desktop system, it's automatically seen as the third SATA drive. Device files are then created in the /-dev directory with names such as dev/sdc1. UDEV works with configuration files in the etc/udev directory. Looks pretty simple, it starts with the standard configuration file in the etc/udev.conf file, and all that does is specify that log messages of an error level are sent to appropriate log files. The strength of UDEV comes in its rules in the rules.d subdirectory. That looks like a lot of rules, let's take a look at the 90-modprobe.rules file. As the name of the file suggests, when media is detected, it runs the mod probe command with appropriate drivers. So if you have a hot plug tape drive, that's detected using the UDEV system, the mod probe command is automatically run to load the driver enabling immediate communication with your system. To see what the UDEV system has already detected, say with the local CD drive, let's the the udevadm command, adm being short for administration, we'll query for all information on the system with device name dev/cdrom. And I have to remember we're querying for all information. There we go, this tells me more about the device file, the actual device name, and related environment variables that are set by UDEV. If you want to monitor changes dynamically, try the UDEV monitor command. Have a USB key or other hot plug device at the ready. Plug in that hot plug device, watch the messages scroll across the screen, unplug that hot plug device, watch as more messages scroll across the screen. Compare those messages to what you see in the ver/log/messages file. They should now look familiar. Just be aware, while the UDEV monitor command is what's specified in the UCP curriculum, it's functional equivalent to the udevadm monitor command. Next, there's the driver manager. I have it in a GUI screen, it comes up on the screen in the hardware drivers window. As listed in the UCP curriculum, the driver manager is the management tool for proprietary hardware drivers. In most cases, mine included, it will be blank. As Ubuntu has made so much progress with hardware, few proprietary drivers are required. It's to the point where the Hardy Heron release, where they restricted repository which would have these drivers has fewer than forty packages. For less than ten hardware components, that's tremendous progress. So for most users, the hardware driver screen will appear blank. You also need to be aware that this screen can be started from a command line in a GUI Desktop with the jockey-gtk command. If you do have any restricted drivers, they can be enabled or disabled through this GUI window.