Sample and Population

Population: let's say you want to see how many people in your city like potatoes.  In statistics,the collection of all the people about whom you are going to draw inferences is called population.  In this case, it is the total number of people in your city.

Sample: a sample can be defined as the subset of the representative population from which the data is collected.  In order to be effective and to be truly representative of the population, the sample has to be random. In this case, it will be a group of people randomly selected from the population.