What is the difference between a fully functional 13 step SDLC and a fully functional 3 step?

The 13-step Software Development Life Cycle (SDLC) provides a detailed framework that encompasses extensive phases such as planning, analysis, design, development, testing, deployment, and maintenance, allowing for thorough documentation and risk management. In contrast, the 3-step SDLC simplifies the process into broader categories: planning, execution, and maintenance, focusing on the essential aspects of software development without delving into granular details. While the 13-step approach is beneficial for complex projects requiring extensive oversight, the 3-step model is more agile and suitable for smaller projects or teams needing quicker iterations.