Bell Curve
Normal Distribution
The bell-shaped curve of a very common distribution of probabilities (hence it being called the 'normal' distribution) where the most probable events in a series of data occur at the highest point, and all other probabilities distribute uniformly below that in both directions, creating rare event 'tails' on the sides.
Origin
The curve's mathematical foundations were first laid by Abraham de Moivre, who privately circulated a Latin pamphlet on 13 November 1733 showing how the bell shape emerges when approximating large binomial distributions — later reprinted in his book The Doctrine of Chances (1738). Carl Friedrich Gauss independently formalised the distribution in 1809 while modelling astronomical measurement errors, cementing the "Gaussian" name. Pierre-Simon Laplace extended both lines of work, and the term normal distribution gradually displaced earlier names in the late 19th century.