Open system

An open system is a system which continuously interacts with its environment. The interaction can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept (see below). An open system should be contrasted with the concept of an isolated system which exchanges neither energy, matter, or information with its environment.

The concept of an "open system" was formalized within the framework of thermodynamics. This concept was expanded upon with the advent of information theory and subsequently systems theory. Today the concept has its applications in the natural and social sciences.

In the natural sciences
In the natural sciences an open system is one whose border is permeable to both energy and mass. In physics a closed system, by contrast, is permeable to energy but not to matter.

Open systems have a number of consequences. A closed system contains limited energies. The definition of an open system assumes that there are supplies of energy that cannot be depleted; in practice, this energy is supplied from some source in the surrounding environment, which can be treated as infinite for the purposes of study. One type of open system is the so-called radiant energy system, which receives its energy from solar radiation – an energy source that can be regarded as inexhaustible for all practical purposes.

They are also known as OSM

In the social sciences
In the social sciences an open system is a process that exchanges material, energy, people, capital and information with its environment.