Unfortunately, when the analysis of variance is significant and the null hypothesis is rejected, the only valid inference that can be made is that at least one population mean is different from at least one other population mean. The analysis of variance does not reveal which population means differ from which others.
Experimenters usually are interested in more information.
They want to know precisely where the differences lie. Consequently, further analyses are usually conducted after a significant analysis of variance. These further analyses almost always involve conducting a series of significance tests.