Final answer:
A population is a group of individuals of the same species living and potentially interbreeding within the same area. This group can form a community when combined with other populations. Together with abiotic factors, they make up an ecosystem.
Step-by-step explanation:
A group of individuals of the same species living in the same area is called a population. A population includes organisms that live in a defined area and have the potential to interbreed. For example, a forest may contain many pine trees, and these trees make up the pine tree population within that forest.
Different populations may live in the same specific area, and when they do, together they form a community. The community includes all living organisms, such as plants, insects, and other animals, interacting within a particular area. On an even broader scale, an ecosystem consists of the community and the non-living, or abiotic, parts of the environment, like water and soil.