Virtualization
Twenty years ago, if you asked the average system administrator what virtualization was they would look at you with a blank stare. We have had virtualization technologies in IT since 1965 when IBM first introduced them in their mainframe computer systems, but for your average company these technologies were relatively rare and out of reach until vendors like VMware and Xen brought these to the mainstream market around the turn of the millennium. The enterprise space did have many of these technologies by the 1990s, but knowledge of them did not disseminate far.
Times have changed. Since 2005, virtualization has been broadly available and widely understood, with options for every platform and at all price points, leaving no one with a need to avoid implementing the technology because it is out of technical or financial reach. At its core, virtualization is an abstraction layer that creates a computer in software (on top of the actual hardware) and presents a standard...