A Bernoulli trial denotes a single event that can have one of two possible outcomes with a fixed probability of occurrence, where one of the outcomes is regarded as a success and the other as a failure. Obtaining heads from flipping a coin and rolling a 3 on the toss of a dice are examples of these events.

 

The Bernoulli distribution is a discrete distribution that refers to the number of successes and failures that can be expected from a number of Bernoulli trials. If the probability of success of the event is , then the Bernoulli distribution function is given by