Selenium is an open-source web testing framework that enables automation of web applications using a toolkit to interact with them like a user, providing a powerful duo when paired with JavaScript for web automation testing tasks such as logging in, filling forms, clicking buttons and navigating pages. Selenium has four tools facilitating test automation: WebDriver, IDE, Grid, and Remote Control. The open-source, cross-platform, and well-documented framework is ideal for testing on any operating system and a global audience, also suitable for mobile apps, generating reports, and integrating with other tools. With the powerful pairing of Selenium WebDriver and JavaScript, rapid and efficient web automation testing can be achieved, guaranteeing effective performance of web applications.