2.1 The Earth System -

System

Open system
Closed System
System feedback

The term "system" comes from the Latin word systema meaning the whole concept of several parts or members, or a collection of interacting objects". A system is composed of three basic elements: first is the set of members or components; second a flow of energy to power them; and third the internal regulation is known as feedback.
The system theory views Earth as a multiple and complex system with interconnecting parts (spheres):

the solid Earth or lithosphere;
the gaseous mantle surrounding our planet, the atmosphere;
the living organisms comprising the biosphere;
the cryosphere which is solid water;
and the liquid water sphere or hydrosphere.