Distributions in outline

The shapes that keep appearing.

Three worth naming

Uniform means every outcome is equally likely, like one die. Binomial counts successes in a fixed number of tries, like heads in ten flips. Normal is the bell curve that sums of many small effects tend towards.

Adding many independent things pushes you towards the normal shape.
That is why heights and measurement errors are bell shaped and incomes are not.

Reading a spread

The average tells you the centre and the standard deviation tells you how far things usually sit from it. Quoting one without the other hides the risk.