A black box is a device which records the data typically in aircraft or ships and which can be retrieved in case of any eventuality. However in software development a Black box assumes a different meaning. A Black Box is a testing technique where the tester does not have any knowledge of the intricacies of the program being tested. The tester may know about the input or the output but does not have any inkling of how the results are achieved. A Black Box component is a compiled program that cannot be altered as a programmer is able to access it only through an exposed interface.