Fancy word for just a simple idea, that the sample space, when I pick something out of the bag and that picking out of the bag is called a trial, there's eight possible things I can do. So when I think about the probability of picking a yellow marble, I want to think about, well, what are all of the possibilities? Well, there's eight possibilities. Eight possibilities for my trial. So the number of outcomes, number of possible outcomes, you could view it as the size of the sample space, number of possible outcomes. And it's as simple as saying, well, look, I have eight marbles. And then you say, well, how many of those marbles meet my constraint that satisfy this event here?