In thermodynamics, a closed system, as contrasted with an isolated system, can exchange heat and work, but not matter, with its surroundings. Here, it is assumed that a thermally isolated (insulated) system can be realized. It is a useful idealization, even if it can only be asymptotically approximated.

For toll roads, a "closed system" refers to a road where a motorist obtains a ticket upon entering the toll road, then pays to toll upon exiting the expressway. The toll is calculated by the distance traveled on the toll road. In contrast, a toll road using an 'open system' consists of mainline toll plazas (a.k.a., toll barriers) at set intervals; it is possible for motorists to get on an 'open toll road' after one toll barrier and exit before the next on, thus traveling on the toll road toll-free most open toll road have ramp tolls to prevent that.

See also

• Dynamical system: Has components and/or flows that change over time.
• Open system: Can be influenced by events outside of the actual or conceptual boundaries.

thermodynamics | Systems theory | Systems | Cybernetics | Fundamental physics concepts

Sistema chiuso | Gesloten systeem