Why is carbon and oxygen cycle are called a cycle?

The carbon and oxygen cycles are called cycles because they describe the continuous movement and transformation of carbon and oxygen through various Earth systems, including the atmosphere, biOSphere, geosphere, and hydrosphere. In these cycles, carbon and oxygen are exchanged among living organisms, the atmosphere, and natural processes like photosynthesis and respiration. This interconnected flow ensures that these essential elements are reused and replenished, maintaining ecological balance and supporting life. The cyclical nature highlights the dynamic interactions between different components of the Earth system.