Information

Information (shortened as info or info.) is a phenomenon relating to knowledge.

Description

Information is:

• That which informs, i.e. an answer to a question
• That from which knowledge and data can be derived
  • As data represents values attributed to parameters, and knowledge signifies understanding of real things or abstract concepts

As it regards data (see also Data (computing)), the information's existence is not necessarily coupled to an observer (it exists beyond an event horizon, for example), while in the case of knowledge, information requires a cognitive observer.

Propagation of cause and effect

At its most fundamental, information is any propagation of cause and effect within a system.

Information conveyance

Information is conveyed either as the content of a message or through direct or indirect observation of some thing.

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.

Encoding

Information can be encoded into various forms for:

• Transmission
• Interpretation

For example, information may be encoded into signs, and transmitted via signals.

Encryption

Information can also be encrypted for safe storage and communication.

Information resolves uncertainty

Information resolves uncertainty.

• The uncertainty of an event is measured by its probability of occurrence and is inversely proportional to that.
• The more uncertain an event, the more information is required to resolve uncertainty of that event.
• The bit is a typical unit of information, but other units such as the nat may be used.
  • Example: information in one "fair" coin flip: log2(2/1) = 1 bit, and in two fair coin flips is log2(4/1) = 2 bits.

Related concepts

The concept that information is the message has different meanings in different contexts.

Thus the concept of information becomes closely related to notions of:

• Constraint
• Communication
• Control
• Data - see Data and Data (computing)
• Form
• Education
• Knowledge
• Meaning
• Understanding
• Mental stimuli
• Pattern
• Perception
• Representation
• Entropy

See also

• Bit
• Data
• Data (computing)
• Data processing
• Data stream
• Data transmission
• Entropy
• Knowledge
• Information system
• Information theory
• Signal
• Signal processing
• Uncertainty
• Units of information

External Links

• Information @ Wikipedia