Software Development Life Cycle Models (SDLC) are systematic and well defined approach for problem solving; it is a series of identifiable stages that software goes during its lifetime. It practiced for developing high quality and reliable software system. In the early years, software was cheaper then hardware. In digital era, hardware is cheaper and software is expensive. So the costs of hardware and software have been reversed due to increased demand of well engineered software products so we have to develop software products due to increasing demand of software in market so for developing a software product we have to follow the models that deliver a quality software product There are many SDLC models available, but in this paper we make our attention in four SDLC models namely; Waterfall model, V shaped model, Spiral model, and Prototype model, there uses, advantages and disadvantages.
