Black box:
In black box testing, the experimenter has no prior knowledge of the target. It simulates a real-world situation where the attacker has limited or no information about the target.
Testers go to a system as an external user, have no credentials, and attempt to find and exploit vulnerabilities without understanding the inner workings or design.
This test is useful for assessing the security of an outsider's perspective and helps identify vulnerabilities that outside attackers can exploit.
White box:
White box testing, also known as clear box or glass box testing, involves a high level of prior information about the target. Provide testers with detailed information about internal processes, source code, graphics and other details.
This type of testing can provide a deeper security analysis by simulating the perspective of an insider or someone with access rights.
White box testing is especially useful in identifying vulnerabilities that are harder to detect externally.
Gray box:
Gray box testing is in between black box testing and white box testing. The tester has partial knowledge of the system, usually some knowledge of the internal workings, but not full access.
This approach combines elements from both external and internal perspectives to provide a balanced security measure.
Gray box testing is often used to test insider threats or attacks where the attacker has some inside information but not complete insider knowledge.
Each entrance exam has its own advantages and is suitable for different situations. Choosing which format to use depends on the specific goals, resources, and needs of your testing project.