Definition:
In statistics, the Kolmogorov–Smirnov test is a nonparametric test of the equality of continuous, one-dimensional probability distributions that can be used to compare a sample with a reference probability distribution, or to compare two samples. It is named after Andrey Kolmogorov and Nikolai Smirnov.
Further Reading:
Book: The DevOps Handbook by Gene Kin, Jez Humble, Patrick Debois and John Willis
