Suppose you want to find out whether the cake/earrings/art you make is worth selling. Will people pay for this? You live in a society with 2000 other families and don’t want to sell outside the society.
There are two ways to make this decision. The first is that you take it to all the 2000 families and ask them, “Will you buy this?” and then decide.
The second is that you select about 10-15 families. You ask them for their opinion and then take a decision.
Which one do you think will take less time and give results faster? The second one, of course.
The technique of selecting a small section of the group we want to study is called sampling.