Test tools are software applications designed to assist in the testing process of other software. They help automate various testing tasks, such as executing test cases, tracking defects, and managing test data. By using test tools, teams can improve efficiency, reduce human error, and ensure that software meets quality standards before release. There are different types of test tools, including unit testing tools, functional testing tools, and performance testing tools. Each type serves a specific purpose, allowing testers to focus on different aspects of the software. Popular examples of test tools include Selenium, JUnit, and LoadRunner.