A binomial is a mathematical expression that consists of two terms separated by a plus or minus sign, such as (a + b) or (x - y). In statistics, the term "binomial" often refers to a binomial distribution, which models the number of successes in a fixed number of independent Bernoulli trials, each with the same probability of success. Binomials are fundamental in algebra and probability theory, playing a key role in various applications, including combinatorics and statistical inference.