Cross browser testing is a type of non-functional testing. It evaluates and verifies the performance and behavior of a website/web app across different browser environments. To know more about cross-browser testing read this article.

In Cross Browser testing, an application is tested across multiple browsers to ensure compatibility. Nowadays, a number of browsers and their versions, os, and their versions and devices and their versions have been released. For cross compatibility, the web application under development has to be tested across various browsers and its versions, os and its version, and devices and its versions. Hence cross-browser testing is performed to test the web applications across various combinations of browsers, os, and devices to ensure that the web application is performing as intended across all such combinations.

No , weblooker is not a web browser

:)

Different web browsers use different rendering engines. This means that web browsers can (and often do) interpret a web page differently to one another. There are many articles on the internet on how to write cross-browser compatible websites.

Yes it is personally i have used it as my web browser