What is Gray Box Testing?

Gray Box Testing is a software testing method which is a combination of Black Box Testing and White Box Testing. In Gray Box Testing, the tester tests the software by having partial knowledge on internal structure of the software. Intention of this testing is to identify the defects on the internal working structure of the software.

For Example: Login account module is designed in such a way that, the account should lock if user logs with invalid authenticate thrice. Here software tester knew the partial knowledge on the internal working structure code of login account module. If login account, doesn’t work for the invalid authenticate, the tester can conclude/guess the problem could be with specific piece of the code.