In order to ensure the quality and reliability of software，We should make every effort in the analysis、Before the end of each development stage, such as design，Strictly review the software technology。But because of the limitation of people's ability，The review didn't find all the mistakes。And a lot of errors will be introduced in the coding phase。If these errors and defects are left to the time when the software is delivered and put into operation，It's going to come out。But by then，It's not just the correction of these mistakes that costs more，And often cause very bad consequences。

Software testing is before the software is put into operation，Analysis of software requirements、Final review of design specification and coding，It is the key step of software quality assurance。How to define software testing，You can say that：Software testing is the process of executing programs to find errors。Or rather，Software testing is a group of test cases designed according to the specification of each stage of software development and the internal structure of the program（That is to input some data and get the expected results），And use these test cases to run the program，To find program errors。

To find program errors，The workload of software testing often accounts for more than 40% of the total workload of software development，The workload of software testing often accounts for more than 40% of the total workload of software development，The workload of software testing often accounts for more than 40% of the total workload of software development，The workload of software testing often accounts for more than 40% of the total workload of software development。therefore，Attach great importance to software testing，Never assume that software development is nearly complete after you write a program，actually，About as much development work remains to be done。Just for testing，Its goal is to find errors in software，however，Finding mistakes is not our ultimate goal。The fundamental goal of software engineering is to develop high-quality software that fully meets the needs of users。