Demography is the scientific study of human populations, including their size, structure, distribution, and dynamics over time. It encompasses a wide range of topics related to population processes and characteristics, such as birth rates, death rates, migration patterns, age distribution, fertility rates, mortality rates, and population growth.

Key aspects of demography include:

1. Population Size and Structure: Demographers study the size and composition of populations, including factors such as age, sex, race, ethnicity, education, occupation, and household structure. They analyze population pyramids, age-sex distributions, and other demographic indicators to understand the demographic profile of a population.
2. Population Dynamics: Demography examines the processes that shape population change, including births, deaths, and migration. Demographers study fertility patterns, mortality trends, and migration flows to assess how these factors influence population growth or decline over time.
3. Population Growth and Decline: Demographers analyze population growth rates and trends to understand the pace and direction of population change. They examine factors such as fertility levels, mortality rates, immigration, and emigration to assess whether a population is growing, shrinking, or stabilizing.
4. Population Distribution: Demography examines the spatial distribution of populations, including patterns of urbanization, rural-urban migration, and regional population disparities. Demographers study how geographical factors, economic opportunities, and social policies influence population distribution and settlement patterns.
5. Population Aging: Demography addresses the aging of populations and its implications for society, including changes in the age structure, health care needs, labor force participation, pension systems, and intergenerational relationships. Demographers study trends in life expectancy, aging populations, and population aging to understand the social and economic consequences of population aging.

Overall, demography provides valuable insights into the dynamics and characteristics of human populations, informing policy decisions, resource allocation, and social planning in areas such as health care, education, housing, and labor markets. It is an essential discipline for understanding the challenges and opportunities associated with population change in contemporary societies.