Cross-device testing is a software testing technique that aims to ensure the functionality and compatibility of a website or application across different devices, such as smartphones, tablets, and desktop computers. This type of testing is crucial in today's digital landscape, where users access applications and websites from a variety of devices with varying screen sizes, resolutions, and operating systems. By conducting cross-device testing, software testers can identify any issues related to responsiveness, layout, performance, and user experience that may arise when the software is accessed from different devices. Automated testing tools are often used in cross-device testing to streamline the testing process and ensure comprehensive test coverage across various devices.