Definitions

• Energy

  The ability to do work. Much of this energy ultimately comes from the sun.
• Flow/transfer

  A form of linkage between one store/component and another that involves movement of energy or mass.
• Input

  The addition of matter and/or energy into a system.
• Output

  The results of the processes within a system
• Store/component

  A part of the system where energy/mass is stored or transformed
• System

  A set of interrelated components working together towards some kind of process