In one sentence, define the concept of "circular economy".
Circular economy refers to a sustainable economic system driven by the principles of eliminating waste and pollution, keeping products and materials in use, and regenerating natural systems.
Complete the following task based on the instruction and optional input provided.### Instruction:
In one sentence, define the concept of "circular economy".

### Output:
Circular economy refers to a sustainable economic system driven by the principles of eliminating waste and pollution, keeping products and materials in use, and regenerating natural systems.