JUnit is a testing framework used to test Java applications. It is an open source project hosted on Github. The JUnit framework has contributed to the development of test-driven development, and is currently the most widely used testing framework for Java. The @After annotation is used to specify a method to be run after each test method. This can be used to clean up resources used by the test, or to take action based on the results of the test. The @Before annotation is used to specify a method to be run before each test method. This can be used to set up resources needed by the test, or to perform actions that need to be done before each test is run. The @BeforeClass annotation is used to specify a static method to be run before any tests in the class are run. This can be used to set up static resources needed by the tests, or to perform actions that need to be done before any tests are run. The @AfterClass annotation is used to specify a static method to be run after all tests in the class have been run. This can be used to clean up static resources used by the tests, or to take action based on the results of the tests.