How does ANOVA work?

ANOVA (Analysis of Variance) is a statistical technique used to compare two or more groups simultaneously to determine whether or not a relationship exists between them. It checks if the means of the groups are significantly different from each other and also checks the impact of one or more factors by comparing the means of the different samples. ANOVA is classified as an omnibus test statistic. This means that it can’t tell you which specific groups were statistically significantly different from each other, only that at least two of the groups were.