Black box Testing treats the method as a “black-box”, so it doesn’t clearly use Knowledge of the internal framework or code. Or in other words the Test engineer need not know the internal working of the “Black box” or application.

Main target in black box testing is on functionality of the procedure as a whole. The term ‘behavioral testing’ is also utilised for black box testing and white box testing is also oftentimes called ‘structural testing’. Behavioral test design is slightly different from black-box test design due to the fact the use of internal knowledge isn’t totally not allowed, but it’s still discouraged.

Each testing method has its own advantages and drawbacks. There are numerous bugs that can't be found using only black box or only white box. Majority of the applicationa tend to be tested by black box testing approach. We need to cover majority of Test Cases in order that most of the bugs will get discovered by blackbox testing.

Black box testing happens throughout the software development and Testing life cycle i. e in Unit, Integration, System, Acceptance and regression testing stages.

Tools used for Black Box testing:
Black box testing tools are mainly record and playback tools. These tools are employed for regression testing that to measure whether new build has created any bug in previous working application functionality. These record and playback tools details test cases in the form of some scripts like TSL, VB script, Java script, Perl.

Advantages of Black Box Testing
 - Tester can be non-technical.
- Used to verify contradictions in actual system and the specifications.
- Test cases can be designed as soon as the functional specifications are complete

 Disadvantages of Black Box Testing
 - The test inputs needs to be from large sample space.
- It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult
 - Chances of having unidentified paths during this testing

Graph Based Testing Methods:
Each and every application is build-up of some objects. All such objects tend to be identified and graph is prepared. From this object graph each object relationship is identified and test cases written accordingly to discover the errors.

Error Guessing:
This is purely based on previous experience and judgment regarding tester. Error Guessing is the art of guessing where errors can be hidden. For this approach there are no specific tools, writing the test cases that cover all the application paths.

Boundary Value Analysis:
Many techniques have tendency to fail on boundary. So testing boundry values of application is significant. Boundary Value Analysis (BVA) is a test Functional Testing technique where the extreme boundary values are preferred. Boundary values include maximum, minimum, just inside/outside boundaries, typical values, and error values.

Extends equivalence partitioning:
 Test both sides of each boundary
 Look at output boundaries for test cases too
 Test min, min-1, max, max+1, typical values

 Limitations of Boundary Value Analysis
 Boundary value testing is efficient only for variables of fixed values i. e boundary.

Equivalence Partitioning:
Equivalence partitioning is a black box testing method that divides the input domain of a program into classes of data from which test cases can be derived.

Comparison Testing:
Different independent versions of same software are used to compare to each other for testing in this method.