The Linux kernel is the heart of the operating system. The kernel provides an interface to all of your computer's hardware. Unlike Windows (tm), almost all Linux device drivers come bundled with the Linux kernel source code (and the binary kernel package that your distro provides). This means that when you install Linux, there's no more driver disk shuffle to get all of your hardware working. Other benefits are that all of these drivers are GPL'd, so you have access to the source code for them. You can see exactly how your hardware works, if your inclined to do so. There are some small problems that come with this.. Certain hardware that doesn't adhere to established standards, or that the manufacturer doesn't want to provide information for, either will not have all of it's features supported, or will not be supported at all. In the past couple of years, it's become increasingly rare to find unsupported hardware.