The base population refers to the initial group of individuals from which a larger population is derived or studied. It is the fundamental unit of analysis in demographic and statistical research, providing a starting point for understanding the characteristics and dynamics of a given population. This term is often used in the fields of sociology, economics, and public health to describe the foundation upon which further analysis and projections are built. The base population can vary in size and composition, but it serves as a crucial reference point for understanding the complexities of human societies and their development over time.