Difference Between Black Box and White Box

The testing of software is always an important part of the development of the software life cycle, be it web-based or mobile application software. Testing a software not only confirms the quality of the software but also provides the developer with a chance to improve if the software has faults. Almost all the software applications need some coding and for the code to run smoothly, they have to go through some tests. For evaluating the functionality and quality of the codes, testers perform black box and white box tests.

Black Box v/s White Box

The main difference between black box and white box is that black box testing tests the internal structure and details of a software application without having any prior knowledge about it whereas, white box testing tests the internal structures of the software applications with having the proper knowledge about it. Black box testing is performed to verify the quality of the system against factors that can cause software failure, while white box testing is performed for the verification of the inner parts of the software.

Black Box testing examines the functions of the application according to its specifications, due to which sometimes it is also known as specification-based testing. Though black box testing can be performed at any stage of the software development, the testing team most of the time performs it during the software life cycle testing.

White box testing, as the name suggests, is the testing where it checks the inner structure of the application against its functions, and the tester in charge can see through the outer box or shell. For designing the test cases in this method of testing, the internal perspective and programming languages of the system are used.

Comparison Table Between Black Box and White Box

What is Black Box?

Black box testing helps in checking the functions of a software application without knowing the inner details of the application. This type of testing mainly concentrates on the input and output of the software application and is only based on the software instructions, requirements, and specifications.

Oftentimes, this type is testing is also named specification-based testing as it tests the functions according to the specifications stated. It is also capable of testing the applications of companies like Google and Windows without knowing how the codes are implemented in their applications, by just evaluating the inputs and outputs. The steps required for carrying out any type of Black Box testing are as follows:

• The Initial step is to examine the requirements and specifications of the system.
• The tester In charge selects the correct input for checking if the SUT processes them accurately. Also, some incorrect inputs are selected to check whether the SUT can detect them or not. 
• The expected outputs are being stated by the tester for all the inputs.
• The tester builds the test cases with the Inputs that are selected.
• The test cases are performed.
• The actual outputs are compared with the expected outputs by the tester.
• If defects are found, they are fixed and tested again.

What is White Box?

White Box testing is the technique used for testing the software in which the internal structures, details, etc are tested to examine the flow of input and output and for improving the design, security, and usefulness of the software. The codes in the white box testing are not covered or hidden in the box and can be seen by the tester in charge, due to which this method of testing is also named Glass box testing or clear box testing. It was termed white box testing because of the see-through concept used in it. The name itself symbolizes the ability to see through the box or the outer shell of the software. The software codes that are tested by the white box testing are as follows:

• Holes in the internal security.
• Faulty structured paths in the process of coding.
• Specific input flow through the code.
• Expected output.

White Box testing can be done on different levels of software development. The sole purpose of conducting this test is to check the status of the working flow of the software application. It tests the series of the pre-set inputs in opposition to the expected outputs to detect a bug if the specified input does not match the expected output. Before performing the white box testing, the tester should be aware of the code of the application. Since it examines the quality of the inner workings of the application, the tester must know the programming languages that are required for testing. After that, the tester should create test cases and perform them. One way for creating cases is by writing codes and the other way includes Manual testing, error testing, trial, etc.

Main Differences Between Black Box and White Box

Conclusion

In conclusion, both the testing are performed to certify the quality of the software for it to become a successful product. Black Box testing test the functionality, while white box testing tests the codes. However, 100% testing can’t be done with both the testing. A tester is mainly responsible for detecting the maximum number of faults in the software for improving the efficiency of the application.

These tests are conducted to state that the application of the software is working as it is expected. This is why it is necessary to understand both these techniques; know the difference between them to effectively choose the correct option.

References

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