Commonly used technology for automated testing in software development includes tools like Selenium, JUnit, and TestNG. These tools help developers and testers execute tests automatically, ensuring that applications function as intended. Automated testing improves efficiency by allowing repetitive tests to be run quickly and accurately, which is essential for regression testing and continuous integration processes. This technology enhances software quality, reduces human error, and frees testers to focus on more complex testing scenarios, ultimately ensuring a smoother development cycle and quicker releases.