Each point represents a dart thrown at the dartboard. The locations of the darts are sampled from either a uniform or normal distribution. In a uniform distribution, all points are equally likely. The uniform distribution is described by the range of possible values in the horizontal and vertical directions. In a normal distribution, center points are more likely than the edge points. The normal distribution is described by its mean (center) and standard deviation (spread).
You can experiment with changing the parameters of the distributions to simulate a skillful dart thrower, one who tends to be consistently off in one direction, or one who is liable to hit anywhere in a particular area. Use a large number of darts to see the area covered by the chosen distribution with the selected parameters.