Answer:
Post hoc tests are used to make all pairwise comparisons between group means
Explanation:
Remember that post hoc tests is a procedure when the F ratio is significant, so this means that post hoc tests can be realized only if F ratio shows us a significant effect, significant difference, etc so we can make all the comparisong between the groups means that we are using in the analysis.
There are a lot of post hoc tests that you can used but the main purpose of the post hoc tests is always the same.
Fior example if you run an ANOVA with 3 different group means first you run the F statistic, and if this F statistic is significant then that means that there is at least one group mean that is different from the others.
so to check the exact differences between the 3 group means, we use post hoc tests