Program validation and testing

• For Complex system, it is necessary to carry out testing that ensure system's intended function.
• There are numerous techniques available for software testing.
• These techniques generate a comprehensive set of tests to ensure the proper functioning of the system.
• The question may be raised in mind that how much testing is sufficient.
• We cannot test the program for every possible combination of inputs there are two types of testing methods.

Black box methods : It checks the system or generates a set of input without knowing the internal structure of the system

White box methods : As the name specifies, this method knows the internal structure of the system and generate the test inputs accordingly.