Information is processed, organized and structured data. It provides context for data and enables decision making processes. For example, a single customer’s sale at a restaurant is data – this becomes information when the business is able to identify the most popular or least popular dish.
|Part of a series on Statistics|
|Information graphic types|
Information can be said to be that portion of the content of a signal or message which conveys meaning. Information is not knowledge itself, but rather the representation of it. Information is often layered: The data available at one level are processed into information to be interpreted at the next level. For example, in written text each symbol or letter conveys information relevant to the word it is part of, each word conveys information relevant to the phrase it is part of, each phrase conveys information relevant to the sentence it is part of, and so on until information at the top level is interpreted and becomes knowledge of the pertinent domain. In a digital signal there is a base level of information that conveys bits which may then be interpreted into the symbols, letters, numbers, or structures that convey the information available at the next level up. The key characteristic of information is that it is subject to interpretation and processing.
The concept of information is used to describe various concepts, including constraint, communication, control, data, form, education, knowledge, meaning, understanding, mental stimuli, pattern, perception, proposition, representation, and entropy.
The information available through a collection of data may be derived by analysis. For example, data may be collected from a single customer’s order at a restaurant. The information available from many orders may be analyzed, and then becomes knowledge that is put to use when the business subsequently is able to identify the most popular or least popular dish.
Information can be transmitted in time, via data storage, and space, via communication and telecommunication. Information is expressed either as the content of a message or through direct or indirect observation. That which is perceived can be construed as a message in its own right, and in that sense, information is always conveyed as the content of a message.
Information can be encoded into various forms for transmission and interpretation (for example, information may be encoded into a sequence of signs, or transmitted via a signal). It can also be encrypted for safe storage and communication.
The uncertainty of an event is measured by its probability of occurrence. Uncertainty is inversely proportional to the probability of occurrence. Information theory takes advantage of this by concluding that more uncertain events require more information to resolve their uncertainty. The bit is a typical unit of information. It is 'that which reduces uncertainty by half'. Other units such as the nat may be used. For example, the information encoded in one "fair" coin flip is log2(2/1) = 1 bit, and in two fair coin flips is log2(4/1) = 2 bits. A 2011 Science article estimated that 97% of technologically stored information was already in digital bits in 2007, and that the year 2002 was the beginning of the digital age for information storage (with digital storage capacity bypassing analog for the first time).