A computer appliance is generally a separate and discrete hardware device with integrated software (firmware), specifically designed to provide a specific computing resource. These devices became known as "appliances" because of their similarity to home appliances, which are generally "closed and sealed" not serviceable by the owner. The hardware and software are pre-integrated and pre-configured before delivery to customer, to provide a "turn-key" solution to a particular problem. Unlike general purpose computers, appliances are generally not designed to allow the customers to change the software (including the underlying operating system), or to flexibly reconfigure the hardware.
