The document discusses the incremental model of software development. It involves constructing a partial initial implementation and then gradually adding more functionality through subsequent releases. Each release builds on previous ones by delivering additional features. The incremental model allows for early delivery of basic functionality, customer feedback, and a divide and conquer approach. However, it requires good planning, design of the complete system upfront, and well-defined module interfaces. The incremental model is best for projects that need early benefits, lengthy development schedules, or new technologies.