A staple in JUnit testing interview questions, be prepared to answer this one. There are two main objectives of the @Before and @After annotations in JUnit 4. The first is to provide a way to set up the test environment before each test is run. This might involve creating objects or files that are needed for the test or initializing variables to certain values. The second objective is to clean up after each test is run. This might involve deleting objects or files that were created during the test or resetting variables to their original values. By using these annotations, we can ensure that each test is run in a consistent and predictable environment. This makes it easier to diagnose and fix problems when they occur.  Another objective of the @Before annotation is to offer a way to execute some set-up code once only before the start of all tests in the class, while @After has the same effect but at the end of all test execution. These changes bring the overall behavior closer to what users would expect from a testing framework. Additionally, it should be noted that @BeforeClass and @AfterClass can only be used on static methods.