What does 'white-box testing' involve?

White-box testing, also known as clear-box testing or structural testing, involves examining the internal structures or workings of an application. This approach allows testers to understand how the software functions, enabling them to create test cases that effectively target specific code paths, logic branches, and internal variables. By having insight into the internal code, testers can ensure that all routes through the software are exercised, which helps identify hidden bugs and performance issues that might not be captured through other testing methods.

This method contrasts with black-box testing, where the tester evaluates the application solely based on its external output without knowledge of the internal workings. Thus, by focusing on the code and architecture, white-box testing provides a comprehensive review of the application's functionality.