A system is a group of things that are linked to each other by the movement of materials and energy. A system is usually open. This means it receives materials and energy from its surroundings. These materials and energy are called input. The inputs are used to carry out processes to keep the system working. Material and energy sent out of the system are called output. A system must hereford have:
- Its components
- inputs
- Processes
- Outputs
Processes and Components
Example: The human body
Inputs: Water, food, climate, oxygen.
Processes: Digestion, absorption, chewing, excretion.
Outputs: Urine, feaces, sweat.
