Final answer:
Demography is the study of populations, including size, distribution, structure, and processes. Population ecology specifically focuses on the number of individuals of one species in an area and how and why that number changes over time.
Step-by-step explanation:
Demography is the study of populations. It encompasses the size, distribution, and structure of populations, as well as population processes such as births, deaths, and migration. Demography uses mathematical tools to describe and investigate how populations change over time. For example, population size and density can affect adaptation and interactions within a population. Life tables are commonly used to display population characteristics. The study of population ecology focuses on the number of individuals of one species in an area and how and why that number changes over time. It involves counting and analyzing population data, such as the population density of an endangered species influenced by the abundance of a specific resource.