Difference between Black box, Grey box and White box testing

Black box testing ->  Without having interior knowledge of software

-> Internal programming not known.

-> Internal workings of an application are not required to be known.

->  Known as closed box, data driven and functional testing.

-> Performed by end users and also by testers and developers.

-> Testing is based on external expectation, internal behavior of application is unknown.

-> Least time consuming and exhaustive.

-> Not suited to algorithm testing.

-> It can be done by trial and error method.

Gray box testing -> Both white box and black box testing are used (Mainly for database testing)

-> Internal programming partially known.

-> Somewhat knowledge of internal working of application are known.

-> Known as translucent testing.

-> Performed by end users and and also by testers and developers.

-> On the basis of high level database diagrams and data flow diagram.

-> Partly time consuming and exhaustive.

-> Not suited to algorithm testing.

-> Data domains and internal boundaries can be tested if known.

White box testing -> With interior knowledge of software

-> Internal programming fully known.

-> Tester has full knowledge of internal working of the application

-> Known as glass, open box, clear box, structural testing or code based testing.

-> Performed by testers and developers.

-> Internal working are fully known and tester can design test data accordingly.

-> Most exhaustive and time consuming.

-> Data domaind and internal boundaries can be better tested.

-> Suited to algorithm testing