The Bernoulli's trial is a fundamental assumption of probability and the base for the simplest form of option pricing model referred to as the 'binomial pricing model'. The Bernoulli trial is a random event with three properties: (a) its result must be characterized by a success or a failure; (b) the probability of a success must be the same for all trials; and (c) the outcome of each trial must be independent of the outcomes of the other trials. The toss of a fair coin satisfies the conditions of a Bernoulli trial. Jakob Bernoulli: (1654 - 1705).
an experiment in which a single action, such as flipping a coin, is repeated over and over
an experiment with two possible outcomes, called success and failure