All cases in which manifestations have exactly two characteristics follow a Bernoulli distribution.
Typical examples are coin flip or medical treatment, which works or not.
Let X be a random variable with and a probability function of
Written in a compact way:
The expected value is defined through:
In case of having a series of Bernoulli events, we are having a Binomial distribution. For example, the out come of a repeated coin flip follows a Binomial distribution.