One-Way ANOVA, or Analysis of Variance, is a statistical method used to compare the means of three or more groups to determine if at least one group mean is significantly different from the others. It helps researchers understand if variations in data are due to different treatments or conditions rather than random chance. In a One-Way ANOVA, the data is divided into groups based on a single factor, such as treatment type or age group. The test calculates the F-statistic, which compares the variance between the groups to the variance within the groups, helping to identify any significant differences among them.