If you teach yourself, you only know one concept and lack relevant practical experience. You don't know how to plan the test work, how to design test cases according to different software, different business processes and different controls, how to identify defects, how to submit defect reports and how to summarize the tests. Without professional training, you can't develop tests or only do some test execution. Moreover, the division of software testing is becoming more and more detailed. For example, black-box testing is divided into manual testing and automated testing, and automated testing is divided into functional testing and performance testing, which requires the development of test scripts. White-box testing is related to code, and it is to do code specification checking and unit testing with developers. However, it is still difficult to learn this knowledge by yourself. Only through systematic study can we better understand and master them and grow rapidly in the software testing industry.