Answer: Ecosystem
An ecosystem is a biological community where living beings interacts with their non-living physical environment. The consists of two components: abiotic factors and biotic factors. The abiotic factors refers to the water, air, soil, temperature and weather. The biotic factors includes all the living beings such as plants, animals, humans and microbes.
A pond is an aquatic ecosystem which consists of water and lower bed rock substrate as abiotic factors and living beings such as aquatic plants, animals like fishes and microbes as biotic factors.