Discrete distributions

Discrete laws model random variables on finite or countable support. The three fundamental laws below form a chain: one trial (Bernoulli), the sum of trials (binomial), then the rare-counting limit (Poisson).

Detailed laws

LawParametersInterpretation
BernoulliSingle success/failure trial, event indicator
Binomial

Number of successes in independent trials

PoissonCount of rare events over an interval

See also