The key distinction between Agile and Waterfall lies in the approach to planning and execution. In the Waterfall methodology, the entire project is planned out in advance, and tasks are completed sequentially. Agile focuses on short iterations, with the ability to make adjustments as needed. This allows for more flexibility and faster adaptation to changes in the project. However, Agile also requires more frequent communication and collaboration among software development team members. Ultimately, it's important to choose a methodology based on the specific needs and goals of your startup.