In this paper, the authors will discuss about attempts to provide a comprehensive view to field of software testing. Now-a-days, software has become an important part of human life. It makes human life so smooth. Many difficult and complex problems are easily handled by using software. So they must ensure that the software they are using must be free of any error or a bug. For developing reliable, flexible and efficient software an organization must perform what they call is "Software Testing" which remains one of the most studied approaches for improving software quality.