Ecology is a branch of Biology that studies the interrelationships between organisms (plants, animals) and their environment.
The word comes from the Greek word oikos which means "house."
A Population is group of organisms of the SAME species living in the same area at the same time and sharing a common gene pool. This group is potentially able to interbreed with one another.
In ecology, the term Community refers to the populations of animals and plants that live within a specific region under similar environmental conditions. These populations of plants and animals live and interact with one another and their environment. Between Humans, the term Community generally refers to a group of people living in the same locality or sharing some common characteristics (i.e. ethnic, cultural or religious).