How and why organisms are hierarchically classified based on evolutionary relationships?

Classification follows an order of simpler first, then the more complex one. The classification of organisms into different groups is helpful in determining the relationship between different organisms, as well as tracing the evolutionary history of a specific organism or group of organisms. The divisions in which organisms are sorted are called taxonomic ranks and they are:
Domain, kingdom, phylum, class, order, family genus and species.

Generally travels west to east but often shifts to north and south