Normal distribution, also called a Gaussian distribution or Bell Curve, is the most common distribution function for independent, randomly generated variables. This normalized distribution helps statisticians calculate the probability of observing any randomly generated value with the distribution. Values that appear close to the center of a Normal Distribution are very common and considered statistically similar. Values that appear at either extreme of the Normal Distribution (or on the “tails” of the Bell Curve) are far less common and considered statistically different from the other values.