Ecology is the branch or aspect of biology that studies the biota (living things), the environment, and their interactions. It comes from the Greek oikos = house; logos = study.
Ecology is the study of ecosystems. Ecosystems describe the web or network of relations among organisms at different scales of organization. Since ecology refers to any form of biodiversity, ecologists research everything from tiny bacteria in nutrient recycling to the effects of tropical rain forests on the Earth's atmosphere. Scientists who study these interactions are called ecologists.