Analysis of variance, or ANOVA, is a statistical test that can be computed in EXCEL. A one-way ANOVA test is intended to test whether the means of several sets of numbers are all the same.
In EXCEL, the means to be tested are input and the program returns an F value, an F critical value and a p value. If F is greater than F critical, it means that the differences in the means are large enough to not be due to random chance and therefore the means are not all the same. If only two means are input into the ANOVA test, it returns the same result as a standard t test.