The Alexa is a one tool that can be used to rank the web site's traffic. It is used to checks the web site traffic. This is one of the most accurate freely available tools to find out how well your site ranks up against millions of other sites on the Web.Cegonsoft

SERP and Alexa are two different term. Alexa mainly tell the traffic of your site while SERP tell you where your page stand on search engines........

Alexa is one of the great tool ,it ranking our websites based upon the high visitors or traffic.In Alexa traffic rank is 1 = its high and 10 = low.But in Google page rank 10 = high pagerank and 1=low page rank based on backlinks.