A population refers to a group of individuals of the same species living in a specific area at a given time. This can include animals, plants, or even microorganisms. Populations are studied in various fields, such as ecology and biology, to understand their dynamics, growth, and interactions with the environment. Populations can vary in size and density, influenced by factors like food availability, predation, and habitat conditions. Researchers often use models to predict changes in populations over time, which can help in conservation efforts and managing natural resources effectively.