Manual testing is the process of manually testing software for defects. It requires a tester to play the role of an end user whereby they use most of the application's features to ensure correct behavior.
The black box testing is done by the Test Engineer, where they can check the functionality of an application or the software according to the customer /client's needs. In this, the code is not visible while performing the testing; that's why it is known as black-box testing.
The Graphical user interface testing process implemented either manually or automatically and repeatedly executed by the third-parties organization instead of the developers or the end-users.
When we have to find and authenticate the particular module or unit of the code, we need the unit testing tools. With the help of these tools, we can build secure design and documentation and decrease the bug count.