The Robot class in Selenium is a Java-based tool designed to automate system-level user interactions that aren't possible through standard Selenium commands, such as handling file upload dialogs, simulating keyboard inputs, and managing native popups. It works by simulating real keyboard and mouse events at the operating system level, offering an extension to Selenium's capabilities for more comprehensive test coverage. To utilize the Robot class, users need to set up Java, an IDE like Eclipse, and Selenium WebDriver, and employ TestNG for test execution. While the Robot class can effectively automate tasks beyond the browser DOM, it comes with limitations, especially in headless or locked environments where it requires an active desktop session to function correctly. Cloud platforms like LambdaTest provide a solution by offering stable environments for executing these tests, bridging the gap between browser automation and OS-level control. Best practices include using the Robot class only when necessary, ensuring active sessions, and handling platform dependencies carefully to ensure consistent test results across different operating systems.