Selenium is a widely-used open-source automation testing framework designed for cross browser testing of web applications across various browsers and platforms. It supports multiple programming languages and offers tools like Selenium WebDriver and Selenium Grid to facilitate efficient testing processes. With the release of Selenium 4, significant updates such as W3C compliance, a new Grid architecture, and relative locators have been introduced, enhancing the stability and performance of tests. Cross browser testing is essential for ensuring consistent user experiences across different browsers and operating systems, and Selenium, when integrated with cloud-based solutions like LambdaTest, helps achieve this by enabling parallel test execution and reducing test flakiness. The framework is compatible with CI/CD tools, which accelerates software release cycles and improves product quality.