Estimating Website Traffic From Search Engine
The first thing you have to consider is there are different types of traffic-related estimations which you might get through search engines. For example, estimated monthly visits from Google, traffic value estimates and number of keyword estimates.
Initially, you get the estimation of global traffic. However, once you navigate to the overview report and hit the organic search tab, it will break down the traffic estimation by 170 countries. There you also get a graph in order to plot the estimation of historic organic traffic. The graph is pretty much interactive, as you can check the traffic stats simply by hover over it. In Fact, you can make it country-specific as well from the drop-down menu. The best part is you can find out all the keywords driving higher traffic to the specific website just by clicking the organic keywords report.
So this is how most of the organic tools work. Remember, the bigger keyword database it holds, the more accurate estimation of traffic it provides. Hence, you can compare multiple tools and choose the right one for yourself.