A Test Suite is a collection of test cases designed to validate the functionality of a software application. It helps ensure that the software behaves as expected by running various tests that cover different aspects of the application. Test suites can be organized based on features, modules, or types of tests, such as unit tests or integration tests. Test suites are essential in the software development process, as they help identify bugs and issues before the software is released. By systematically executing the tests within a suite, developers can maintain the quality of the software and ensure that new changes do not introduce new problems, supporting practices like Continuous Integration and Agile Development.