The population refers to the entire group that is the subject of the study. It includes every individual or element that possesses the characteristics under investigation.
A sample is a subset of the population. It consists of a smaller number of individuals or elements selected from the larger population.
The purpose of selecting a sample is to make inferences or draw conclusions about the population based on the analysis of the sample data.
Using the previous example, instead of collecting data from every household in the country, you might select a sample of households to represent the entire population.