Information theory studies the quantification, storage, and communication of information. It was originally proposed by Claude E. Shannon in 1948 to find fundamental limits on signal processing and communication operations such as data compression, in a landmark paper entitled "A Mathematical Theory of Communication".(wikipedia quote) What, however, is a source and destination of information, is not a subject of that theory. Later on, information naturally occurs in AI theory as a sensory input to an intelligent agent. The picture shows an "intelligent information cycle", intelligent agent percepts information via sensors from its environment, analyzes them and decides on how to act towards the environment, actions are performed via actuators, and the cycle goes on continuously. The same model is used to describe responsiveness to stimuli, one of fundamental characteristics of living things. Others are: metabolism (cataboli