Software engineering is a detailed engineering study for the design, development and maintenance of software. Software engineering was introduced to address the problems of low quality software projects. Problems arise when software generally exceeds deadlines, budgets and reduced levels of quality. Ensures that the application is built consistently, correctly, on time, within the budget and within the requirements. The demand for software engineering also arose to address the immense rate of change in user requirements and the environment in which the application is supposed to work. So, my question is, what is software reengineering?