CBSE Class 8 Answered

Ecosystem is a system formed by the interaction of a community of organisms with their physical environment. It consists of all the organisms (like plants, animals, microbes etc.) living in a particular area, as well as all the nonliving, physical components of the environment with which the organisms interact, such as air, soil, water, and sunlight.

OR

An ecosystem can be defined as a group of living and non-living things which are interdependent and are found in a particular type of environment.