Bernoulli trial

A Bernoulli trial is the single-trial building block that the binomial distribution stacks up: one shot, one flip, one yes or no answer. If a player makes 78% of free throws, one attempt is a Bernoulli trial with $p = 0.78$, mean $0.78$, and standard deviation $\sqrt{0.78(0.22)} = \sqrt{0.1716} \approx 0.414$. Counting successes across $n = 20$ independent attempts turns those trials into a binomial random variable. The trials have to be independent and share the same $p$, which is exactly what the binomial setting demands. The idea is squarely AP content, since it is just the binomial setting one trial at a time, but the name Bernoulli is not vocabulary the AP course framework uses.