What is the meaning of ‘Black-box Testing’?

Black-box Testing also is known as functional testing is a strategy to test only the functionality of the application and not the structure of the program. The internal mechanism of the system is ignored and the main aim is to focus on outputs generated as a response to select inputs and other conditions of execution.

The test is limited to validation of the output instead of the process how the output is reached. There is no requirement for programming knowledge or even the implementation logic. The test is applicable only at higher testing levels like Acceptance Testing and System Testing. A black box is basically software where inputs are fed and the outputs are expected. Thus, in this type of testing the focus is on giving a known input to obtain a known output. It is usually followed by carrying an acceptance testing. Various techniques used in the black-box texting are :

• Boundary-value analysis
• Error guessing
• Syntax testing
• State transition testing
• Equivalence partitioning