A cohort study is a type of observational research where a group of people, known as a cohort, is followed over time to observe outcomes related to specific exposures or risk factors. Researchers collect data on the cohort's characteristics and behaviors, such as lifestyle choices or environmental exposures, to determine how these factors may influence health outcomes, like the development of diseases. Cohort studies can be prospective, where participants are followed into the future, or retrospective, where researchers look back at existing data. This method is commonly used in fields like epidemiology and public health to identify associations between risk factors and health outcomes, contributing valuable insights for improving health interventions.