The document discusses the software development life cycle (SDLC), which is a structured process used to design, develop, and test good quality software. The SDLC involves six main phases: planning and requirements analysis, defining requirements, designing architecture, developing the product, product testing, and deployment and maintenance. Following an SDLC model provides benefits like better project management, transparency, and predictable results, though it also has disadvantages like differences between documentation and implementation and constraints on developers.