An association of individuals of different species living in the same habitat and having functional interactions is
An association of individuals of different species living in the same habitat and having functional interactions is a biotic community.
The ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.
A population is the number of organisms of the same species that live in a particular geographic area at the same time, with the capability of interbreeding.
Each organism has an invariably defined range of conditions that it can tolerate, diversity in the resources it utilizes, and a distinct functional role in the ecological system, all these together comprise its niche.