If you want to know information about a page there are many tools. I have seen many tools that works same so there is no such difference and produces same results.
Most of these sites contain Alexa rank, compete rank, Google page ranks, site title, site value etc.
Pageinsider has zero page rank, I do not know what has been wrong with this? But its Alexa rank is well under 4500K and compete rank is even better under 2600K. I searched for techshali.com and there was already data about this. Someone may have checked about it. It shows website description, website owner address and contact number, daily ad revenue, site worth, speed etc. These data are generated from Alexa.com.
Second tab is for rank, that provides deep insight for rank. Ranks are based on Alexa, Compete, Quantcast and Google PageRank. But whole section is based on ALexa.com, but it uses of data is smart. You will know your users in country, in city based on numbers and percentage.
The information you see on this website are allowed by website owners, if one has hidden his information you would not be able to see the info of a website.