What is the difference between a population and a sample in a survey?

In a survey, the population refers to the entire group that is being studied, such as all students in a school. A sample is a smaller group selected from the population to represent the whole, like a few classes from the entire school. For example, if we want to understand the favorite subject of students in a school, the population would be all the students in the school, while the sample would be a specific number of students chosen to represent the entire student body.