Grey Box Testing

Grey Box Testing is a hybrid testing approach that combines aspects of both black box and white box testing. Testers have a partial understanding of the system's internal structure, algorithms, and data, which allows them to design more targeted and effective test cases while still testing from a user's perspective.

Example: A tester performing Grey Box Testing on a web application's user registration form might have knowledge of the database structure, including the specific fields for storing user data and any validation rules at the database level. Using this internal knowledge, they could create a test case to see how the system handles a username that exceeds the database's maximum character limit, a scenario that a typical black box test might not uncover.