Definition for Closed system
From Biology Forums Dictionary
Is an economy in which no activity is conducted with outside economies. A closed economy is self-sufficient, meaning no imports are brought in and no exports are sent out, the goal being to provide consumers with everything they need from within the economy's borders. A closed economy is the opposite of an open economy, in which a country conducts trade with outside regions. For example, earth is a closed system, the material inputs Earth can provide are finite and so is the waste- absorbing capacity .