Analysis of Variance, a hypothesis testing technique allowing you to determine whether the differences between samples are simply due to random sampling errors, or whether there are systematic treatment effects that cause the mean in one group to differ from the mean in another. Excel has a built-in analysis tool for ANOVA.
ANOVA can be one-way or two-way. You should use two-way when there is more than one independent (categorical) variable being assessed:
ANCOVA (Analysis of Covariance) is a general linear model testing covariance which uses some elements of ANOVA and some elements of regression analysis.
MANOVA (Multivariate Analysis of Variance) is an ANOVA test with multiple dependent variables.
General linear models
An ANOVA procedure used to test hypotheses in statistical experiments, factoring the results of known quantities along with predicted values.