A group of the same organisms that live in the same area at the exact same time is referred to as a population. Population is a term used by ecologists.
Ecologists study populations in order to see how they interact with the environment in which they live. They study how different populations interact with one another. Populations are also studied in order to determine population growth. As organisms are born and die, it can affect the population growth. Some organisms also leave the population, which is known as emigration. When they enter a new population, it is referred to as immigration.