Selenium WebDriver is an automation testing framework that automates the testing of web applications on different browsers. It empowers testers and developers to write automation test scripts effortlessly in multiple programming languages, such as Java, Ruby, NodeJS, Python, C#, PHP, Perl, and many more. Selenium supports cross-browser testing on almost all popular web browsers, including Google Chrome, Apple's Safari, Mozilla Firefox, Microsoft Edge, Opera, etc., where the Selenium test scripts written in different programming languages can run smoothly. It also supports cross-platform testing, i.e., the test cases can run simultaneously across multiple supported operating systems. The platforms supported by Selenium include Windows, Linux, Mac OS, and Solaris. Selenium is one of the top automation testing tools as it allows developers and automation testers to create flexible and robust automation test cases.