The bell curve, also known as the normal distribution, provides a foundation for the majority of statistical procedures currently used in sociology. It can be thought of as a histogram of a continuous variable, but with such fine distinctions between outcomes that it is not possible to differentiate individual bars, so that the histogram appears to be a smooth line in the shape of a bell. Beneath this line are 100 percent of the possible outcomes, with the x-axis describing the range of possible outcomes and the y-axis describing the proportion or probability for each outcome.