JUnit Annotations are a type of syntactic meta-data that can be used to improve the readability and organisation of Java source code. Annotating variables, parameters, packages, methods, and classes is possible. In Junit4, annotations were introduced, making Java code more readable and easy.
JUnit is generally used to test all of your application's units or components, such as classes and methods. It aids with the creation and execution of repeatable automated tests, ensuring that your code performs as expected. Selenium automation testing for web apps and webpages is also possible with JUnit.
JUnit understands that the public void method to which the Test annotation is attached can be used as a test case. JUnit creates a new instance of the class before invoking the annotated method to run the method. JUnit will report any exceptions thrown by the test as a failure.
The language used in JUnit annotations is similar to comments that developers make in code. They can be used to provide context and additional information about the test case. In addition, they can be used as documentation for the developer or other team members who might have to work on this code.