Ecosystem refers to the RELATIONSHIP between plants and animals in a certain HABITAT. These are the Food Chain(dependency on eachother who eats what), Co-living spaces or competitive relationships such as fight for resources. Therefore, Ecosystem is relationship between species in a Habitat.

Biodiversity -GENETIC or PHYSICAL Differences of animals and plants within species, between species.

Ecosystem- includes RELATIONSHIP in a HABITAT between the LIVING ORGANISM as well as the NON LIVING THINGS that INTERACT with EACH AREA in a given environment or area.