Information

The concept information covers signs, signals and messages with their syntactic, semantic and pragmatic aspects.

Uncertainty and thus information content of a random event i is quantified as negative logarithm of its probability:

 i = - ld pi ,

where ld denotes the dual logarithm and p_i the probability of the associated event.

The quantity of an information stream produced by an ergodic source (entropy) is defined by Shannon's equation.