The software development methodology that emphasizes collaboration and flexibility is known as Agile. Agile methodologies focus on iterative development, where requirements and solutions evolve through collaborative teamwork. Agile fosters regular feedback and adaptive planning, allowing teams to respond quickly to changes in project scope or user needs. This approach improves project transparency and encourages continuous improvement through practices like sprint planning and retrospectives. Overall, Agile empowers teams to deliver high-quality software in a fast-paced development environment.