A random variable is one whose value is unknown or a function that assigns values to each of an experiment’s outcomes. A random variable can be discrete or continuous.

For example, stock prices are discrete random variables, because they can only take on certain values, such as $10.00, $10.01 and $10.02 and not $10.005, since stocks have a minimum tick size of ...

Common examples of discrete distributions include the binomial, ... The probabilities of random variables must have discrete (as opposed to continuous) values as outcomes.