This Testing Technique examines the basic program structure and it derives the test data from the program logic; Ensuring that all statements and conditions executed at least once. It is called as

White box testing examines the program's internal structure, logic, and code to derive test cases. It ensures all statements and branches are executed at least once (statement and branch coverage). Black box testing doesn't look at code, gray box combines both approaches, and 'closed box' isn't a standard testing term (black box is the correct opposite of white box).