In research, a population refers to the entire group of individuals, objects, events, or procedures that possess specific characteristics and are of interest to the researcher. It is the main focus of a scientific query, and researchers conduct studies to derive conclusions that will apply to the entire population. However, due to the large sizes of populations, researchers often cannot test every individual in the population because it is too expensive and time-consuming. Therefore, research studies are usually carried out on a sample of subjects rather than the whole population. A sample is a specific group that researchers collect data from. It is a subset of the population, and the size of the sample is always less than the total size of the population. The use of population and sample in statistical inference is crucial to make sure that the data collected is suitable for the problem at hand. Researchers define the study population by geographic location, age, sex, occupation, religion, ethnic group, and other attributes and variables.