First, a question: How far do you think the average observable star is from Earth?
If you are not an astronomer, this is the kind of question that might make you shrug your shoulders and respond, "I have no idea."
But let's say I give you the distance to 100 random stars. Do you think your guess would then be pretty close by using this data? Actually it would. Despite the fact there are billions and trillions of stars, knowing the average distance to just 100 would give you an enormous amount of information about how far, on average, it is to all stars.