This report provides a comprehensive overview of Software Development Life Cycle (SDLC) models, specifically focusing on Waterfall and Agile methodologies, within the context of developing an online hotel booking application. The report begins with an introduction to SDLC, highlighting the significance of structured approaches in software development. It then delves into the characteristics, advantages, and disadvantages of both Waterfall and Agile models, explaining their suitability for different project scenarios. The report further details the functional requirements of the hotel booking application, including user login, registration, and database design, with an emphasis on the relational database structure. The report incorporates visual aids such as Entity Relationship Diagrams (ERD), Data Flow Diagrams (DFD), and Use Case diagrams to illustrate the system's architecture and user interactions. Furthermore, the report presents an in-depth analysis of the chosen methodology, justifying the selection based on project requirements and team dynamics. Overall, the report serves as a valuable resource for understanding SDLC models and their practical application in software development projects.