A system in which there is no transfer of material across the system boundary. Differential material and energy balances are used to describe closed systems. A batch process takes place in a closed system.
Geology and Earth Sciences
A system that is able to exchange energy, but not matter, with its surroundings.
Geography
A system marked by clear boundaries that prohibit the movement of energy across them. Entropy in a closed system can never decrease. See R. Chorley (1964).