Physical information Physical information Physical information is a form of information. In physics, it refers to the information of a physical system. Physical information is an important concept used in a number of fields of study in physics. For example, in quantum mechanics, the form of physical information known as quantum information is used in many descriptions of quantum phenomena, such as quantum observation, quantum entanglement and the causal relationship between quantum objects that carry out either or both close and long-range interactions with one another. In a somewhat general sense, the information of a given entity can be interpreted as its
N-entity the lowest, "i.e.", the physical layer, to the highest, so that the -th layer is above the "n"-th layer and the -th layer is below. N-entity In telecommunication, a "n"-entity is an active element in the "n"-th layer of the Open Systems Interconnection--Reference Model (OSI-RM) that (a) interacts directly with elements, "i.e.", entities, of the layer immediately above or below the "n"-th layer, (b) is defined by a unique set of rules, "i.e.", syntax, and information formats, including data and control formats, and (c) performs a defined set of functions. The "n" refers to any one of the 7 layers