Like the binomial and hypergeometric distributions, the geometric distribution is related to the Bernoulli(p) distribution. Unlike the binomial and hypergeometric distributions, the geometric distribution does not have a bounded support. In this lesson, the geometric distribution is introduced. Its probability mass function (PMF) is derived, as is the mean. Expressions for the cumulative distribution function (CDF), variance, and moment generating function (MGF) are provided. The concept of a memoryless distribution is defined. Finally, examples are provided to illustrate all of these.