"All machines consume input, perform some sort of work, and yield output. A telephone, for example, converts sound energy to an electrical signal and back again to audio to enable conversation. An engine imbibes fuel (steam, fission, petrol, or elbow grease) and transforms it into work. And a blender devours rum, ice, lime, and curacao, and stirs vigorously to produce a Mai Tai. (Or, if you prefer something more metropolitan, try some champagne and pear nectar to enjoy a Bellini. The blender is truly a flexible and remarkable machine.)
"Because software transforms data, each application is also a machine--albeit a 'virtual' one, given the absence of physical parts..."
