The test of a given statistical hypothesis in which only a value of the statistic that is, for example, sufficiently large will lead to rejection of the hypothesis tested.
The statistical tables for F, for 
and for 
provide the critical values for a one-tailed test in which the entire α region is assigned to the upper end of the sampling distribution when the hypothesis tested is true.
and for provide the critical values for a one-tailed test in which the entire α region is assigned to the upper end of the sampling distribution when the hypothesis tested is true.