Black Box Testing, often termed as Behavioural Testing, is a software testing technique in which the tester is not aware of the internal structure of the application being tested. This method can be applied to every level of application testing including unit, integration, system, and acceptance.

This approach is called Black-Box because the software program is like a black box, inside which a tester cannot see. This method attempts to find out errors related to the incorrect or missing functions, initialization or termination errors, interface errors, behavior or performance errors, etc. It is end-to-end high-level testing.