An ecosystem is a biological community of living organisms (biotic components) and their non-living environment (abiotic components) interacting as a unified, self-regulating system. These components are linked through nutrient cycles and energy flows. For instance, plants (producers) use sunlight and nutrients to create their own food through photosynthesis. This energy is then transferred to animals (consumers) that eat the plants, and then to other animals that eat them. When organisms die, decomposers like fungi and bacteria break down their remains, returning essential nutrients to the soil for producers to use again.
Ecosystems can be of any size, from a small pond to a vast desert or the entire planet. The balance and health of an ecosystem depend on the intricate relationships and flow of energy between all of its components. Disrupting one part of the system, like introducing an invasive species or altering the climate, can have cascading effects on the entire network, potentially leading to instability or even collapse.