Add this Tag for questions on information theory applied to physics, especially in the fields of statistical mechanics and thermodynamics, the black hole information paradox, complexity of dynamical and physical systems and questions to do with whether information is conserved by physical systems. Use the tag quantum information if your question is to do with information theoretic concepts applied to quantum states.
An intuitive definition of a system's information content in binary digits (bits) is the number of yes / no questions that must be answered to uniquely and unambiguously specify a system. The information content of a physical system is defined by the related concepts of Shannon entropy and Kolmogorov Complexity. The question of whether "information is conserved" in physical processes, especially throughout an object's falling into a black hole, is tantamount to the asking of whether there is a one-to-one mapping of the state of a system before a physical process to the state after that process, and thus whether the former state can be uniquely inferred from the ending state. The study of statistical mechanics and thermodynamics has also been furthered by the application of information theoretic ideas.