The binomial distribution models experiments in which a repeated binary outcome is counted. Each binary outcome is called a “Bernoulli trial”. The binomial distribution (p + q)n is determined by the number of observations n, and the probability of occurrence, denoted by p + q (the two possible outcomes). This provides a model for various probabilities of outcomes that can occur. To determine the probability of each outcome, the binomial distribution has to be expanded by the number of observations – by raising p + q to the nth power.
