All terms in this list:

what is an ecosystem: An ecosystem is a community of living and non-living organisms

whats an example of an ecosystem: An ecosystem consists of the biological community that occurs in some locale, and the physical and chemical factors that make up its non-living or abiotic environment. There are many examples of ecosystems -- a pond, a forest, an estuary, a grassland.

what is bio-diversity: bio-diversity is the variation of animals in an ecosystem.

abiotic factor: the non-living parts of an ecosystem (water, sunlight, air...)

habitat: A specific place or natural conditions in which a plant or animal lives.

consumer: One who, or that which, consumes.

decomposers: organisms that break down dead,decaying material and return nutrients to the soil ( natures recyclers!)
Examples are mushrooms, earthworms, bacteria, fungi