The lay of the land [pervasive computing system]

A pervasive computing system is usually built upon a familiar set of technologies that have matured in the past two decades: microprocessors, high-speed data communication, sensors, pattern recognition, and sophisticated human interfaces. Yet, the ideas behind their application in a pervasive setting can be traced back to the origins of mechanical computing. Modern pervasive computing differs from these primitive examples because it attempts to hide or at least partially conceal the computer itself.