JUnit is a popular testing framework for Java programming language. It provides a simple and efficient way to write unit tests for your Java code, allowing you to ensure that your code functions as expected and continues to work correctly as you make changes. Key Features of JUnit: 1. Annotations: JUnit uses annotations to identify methods that specify test cases and setup/teardown operations. Annotations include `@Test`, `@Before`, `@After`, `@BeforeClass`, and `@AfterClass`. 2. Assertions: JUnit provides a set of assertion methods such as `assertEquals`, `assertTrue`, `assertFalse`, `assertNotNull`, etc., to validate expected outcomes of tests. 3. Test Runners: JUnit includes various test runners that execute test cases and report results. The default runner is `BlockJUnit4ClassRunner`, but JUnit also supports parameterized tests and suites. 4. Parameterized Tests: JUnit allows you to write parameterized tests using the `@ParameterizedTest` annotation, wh...