According to the testing techniques used, software testing can be divided into black box testing and white box testing.
(1) Black box testing
Black-box testing is to treat the software (program) as a black box with input and output. It regards the program as a mapping from input domain to output domain. As long as the input data can output the expected result, it does not need to care about the inside of the program. How to achieve it, as shown in Figure 1.
Figure 1 Black box test
(2) White box testing
White box testing is also called transparent box testing. It means that testers understand the logical structure, path and running process of the software program, and obtain results according to the execution path of the program during the test. White-box testing is to treat the software (program) as a transparent box, and testers clearly know every step of the process from input to output, as shown in Figure 2.
Figure 2 White box testing
Compared with black-box testing, white-box testing has higher requirements for testers. It requires testers to have certain programming skills and be familiar with various scripting languages. However, in software companies, black-box testing and white-box testing are not clearly defined. When testing a piece of software, black-box testing and white-box testing are often combined to conduct a complete and comprehensive test of the software.