Information is a term variously used depending on contexts, but closely related to such concepts as knowledge, negentropy, difference, communication, truth, representation, and mental stimulus. Although many people speak of the advent of "information age" or "information society," and information technologies, information science and informatics are somewhat in the spotlight, the definition of "information" something allegedly very important for our society, is not necessarily well-articulated or intensively debated, though notable exceptions exist.
Here are a list of major meanings, in roughly an order of narrowest to the broadest:
First, information is negative entropy, or some knowledge that can be used to reduce uncertainty (about future events or past or current conditions). That is, information is useful truth or knowledge about something which people can use when making judgments and take actions. It may be called intelligence in certain contexts. The term disinformation in certain context mean some false knowledge to manipulate the way recipients reduce uncertainty and form expectations. It assumes that wrong perception is not information.
Second, information is often contrasted with noise in communication. Information in communication is a message, something to be communicated, from the sender to the receiver, while noise is something that could block communication and/or bring misunderstanding. In this case, information does not have to be accurate. It may be a lie, or just a sound of a kiss which is to be transferred. This model assumes a sender and a receiver. Information is not assumed to be something that can be extracted from an environment through observation or measurement, for example. It is a message, a creation of the sender.
Third, information is a represented pattern. It assumes neither accuracy nor directly communicating parties. It assumes the separation between object of representation and its representation, and involvement of conscious mind recognizing this relationship. An economy and economic statistics[?] are in such a relation - economy is the object which is represented by the statistics, however inaccurate. What is commonly referred to as data in computing, statistics, and other fields, are information in this sense. The electro-magnetic patterns in a computer network and connected devices[?] are related to something other than the pattern itself, such as text to be displayed and keyboard input. Signals[?], signs, symbols[?] are also in this category. Painting and drawing contain information in a sense, and to the extent, that they represent something such as an assortment of objects on a table, profile[?], or a landscape In other words, when a pattern of something is transposed to a pttern of something else, the latter is information. This type of information still assume some involvement of conscious mind, either as a someone who construct the representation, or someone who interpret the represented. When one construct a representation of an object, one can selectively extract from the object (sampling) or use a system of signs to replace (coding), or both. The sampling and conding result in representation. Example of the former is "sample" of a product, the latter is "verbal description" of a product (and both contain information of the product, however inaccurate). When one interpret representation, one can predict a broader pattern from a limited number of observation (inference) or understand the relation between patterns of two different things (decoding). Example of the former is to sip a soup to know if it is spoiled; the latter is to examine footsteps[?] to know the animal and its condition. In both cases, information sources are not constructed or presented by some "sender" of information. To repeat, information in this sense does not assume direct communication, but it assumes involvement of some conscious mind.
Fourth, information is any type of sensory input. When a body receives an input, it transforms the input into electric pulses in nerve system. This is regarded information by some. The idea of representation is still relevant, but in a slightly different manner. That is, while abstract painting[?] does not contain any information (it does not represent anything), when viewer sees the painting, the pattern of paint itself is transformed into electric pulses creating a representation of the painting. Defined this way, information does not have to be related to truth, communication, or representation of an object. Entertainment in general that are not informative, including music, performing arts[?], amusement park, works of fiction and so on are sources of information in this sense, if not any of above. What does not qualify as an information source is those materials which do not function as sensory input. For example, food supply both nuturition and taste for those who eat it. The former is not information, whereas the latter is. Cognitive science deals with information in this sense.
Finally, information is any type of patterns that influences the formations and transformations of other patterns. DNA qualifies as a source of information in this sense. The genetic information is often thought to exist without any conscious mind which perceives the pattern. The information in this sense is a pattern which influences other patterns such as development of a body. Systems theory seems to refer to information in this sense at times, assuming information does not necessarily involve any conscious mind, and patterns circulating (due to presence of a feedback) in the system can be called information. In other words, it can be said that information in this sense is something potentially perceived as representation, though not created or presented for that purpose. When someone suggests that this world is made of information, information is defined in this way. (See, Gregory Bateson) When Marshall McLuhan speaks of media and their effects on human culures, it is about the structure of artefacts that in turn shape our behaviors and mindsets. Pheromone is often said to be information in this sense, too.