Alexa Internet, Inc. is a California based subsidiary company of Amazon.com that is well-known for its toolbar and website. This website founded in 1996 by Brewster Kahle and BruceGilliat and grew out of a vision of intelligent Web navigation continuously improving upon through its users. Since then, Alexa users have downloaded millions of Toolbars and Alexa has created one of the largest Web crawls and developed the infrastructure to process and serve massive amounts of data.
They provide ranking by gathering data (Likes the browsing data from people’s) from the Alexa toolbar. Another thing is they measure traffic rank by country, if a website is local, Alexa rank will high for the its country and lower for the world rank. You will find out the rank of your website through by Alexa ranking. To facilitate monitoring in Alexa ranking, you require a widget that can be downloaded on the official website alexa.com.