A case-control study is a type of observational research used to identify factors that may contribute to a specific outcome, such as a disease. In this study design, researchers compare two groups: those who have the outcome of interest, known as the cases, and those who do not, called the controls. By examining the differences in exposure to potential risk factors between these groups, researchers can infer associations. This method is particularly useful for studying rare diseases or outcomes, as it allows researchers to gather data more efficiently. However, case-control studies can be subject to biases, such as recall bias, where participants may not accurately remember past exposures.