Final answer:
Epidemiology is the study of how diseases affect populations, while experiments involve manipulating variables to understand cause and effect relationships.
Step-by-step explanation:
Epidemiology is the study of how diseases are transmitted and how they affect a population, focusing on health-related events in populations. It examines the causes and effects of health-related events, such as diseases, in order to prevent and control their spread. On the other hand, experiments involve manipulating variables under controlled conditions to understand the cause and effect relationship between them. Researchers apply a treatment to a group of subjects in order to isolate the effects of the treatment on an outcome variable by comparing it to a control group.