In statistical theory (https://en.wikipedia.org/wiki/Statistics), the concept of variance is defined as follows:
The expectation (https://en.wikipedia.org/wiki/Expected_value) of the squared deviation of a random variable from its mean or, in other words, it is a measurement of just how far a set of random numbers are spread out from their average value.
The practice of the analysis of variance (or simply variance analysis) involves a data scientist evaluating the difference between two figures. Typically, this process applies financial or operational data in an attempt to identify and determine the cause of the variance. In applied statistics, there are different forms of variance analysis.
Variance and the analysis of variance ...