Firewalls
Firewalls emerged as a new technology in 1990s but its idea was present near two decades back. Historical context of "Firewall" is quite literal. It was in use to describe a barrier that separates a portion of a building dealing with fire, like a stove or a kitchen, from the rest of the structure. Later firewall found its use in connection with steam engines. It was described as a wall which separates an engine fire from passenger cars. Firewall ideas were greatly matured when Jeff Mogul from Digital Equipment Corporation published his papers in 1988 . His work described various processes that could be used to make networks secure. It was Marcus Ranum of AT&T Bell Laboratories who proposed the design of firewall and its components. He also coined the term "Firewall" for this quickly maturing technology. His work got much attention in 1990 and firewalls gained commercial popularity