This is part three of Ars’ guide about virtualisation. “Part 1 described three ways in which a component might be virtualized; emulation, “classic” virtualization, and paravirtualization, and part 2 described in more detail how each of these methods was used in CPU virtualization. But the CPU is not the only part of a computer that can use these techniques; although hardware devices are quite different from a CPU, similar approaches are equally useful.”