The ANOVA makes a general statement about whether or not there are
significant differences between the data groups. Once the result is
positive (p < 0.05), you need to employ additional tests to find out
which of the multiple comparisons that are possible for your data set are
significant. So-called posthoc tests perform multiple comparisons of a set
of several data groups.
This is a companion discussion topic for the original entry at https://www.xltoolbox.net/anova.html?help=6.53