Selenium is a now a preferred choice for testing GUI, functionality of web applications because of its robust, open-source software testing framework. Selenium test automation tool is used across diverse industries to test applications for performance, reliability, compatibility and overall quality of web applications. Selenium’s open source licensing and its support for multiple browsers, languages, and platforms also make it the core engine for various commercial browser automation tools. Selenium, and Selenium 2 (better known as WebDriver), are advanced test automation tools designed for effectively performing web browser based test automation, Selenium UI testing, Load testing and more.