Tips & Definitions:
Information - Information is a term with many meanings depending on context, but is as a rule closely related to such concepts as meaning, knowledge, instruction, communication, representation, and mental stimulus. Although many people speak of the advent of the "information age," the "information society," and information technologies, and even though information science and computer science are often in the spotlight, the word "information" is often used without careful consideration of the various meanings it has come to acquire. Often information is viewed as a type of input to an organism or designed device. Inputs are of two kinds. Some inputs are important to the function of the organism (for example, food) or device (energy) by themselves. In his book Sensory Ecology, Dusenbery called these causal inputs.

Other inputs (information) are important only because they are associated with causal inputs and can be used to predict the occurrence of a causal input at a later time (and perhaps another place). Some information is important because of association with other information but eventually there must be a connection to a causal input. In practice, information is usually carried by weak stimuli that must be detected by specialized sensory systems and amplified by energy inputs before they can be functional to the organism or device. For example, light is often a causal input to plants but provides information to animals. The colored light reflected from a flower is too weak to do much photosynthetic work but the visual system of the bee detects it and the bee's nervous system uses the information to guide the bee to the flower, where the bee often finds nectar or pollen, which are causal inputs, serving a nutritional function. The most important meanings of information are identified in the following sections roughly in order of narrowest to broadest.

Information as a message: Information is a message, something to be communicated from the sender to the receiver, as opposed to noise, which is something that inhibits the flow of communication or creates misunderstanding. If information is viewed merely as a message, it does not have to be accurate. It may be a lie, or just a sound of a kiss. This model assumes a sender and a receiver, and does not attach any significance to the idea that information is something that can be extracted from an environment, e.g., through observation or measurement. Information in this sense is simply any message the sender chooses to create.