This comprehensive guide to agile software development provides a foundational understanding of agile principles, practices, and methodologies. It introduces the Agile Manifesto and its four guiding values, and explores iterative and incremental development, continuous integration and delivery, and other key agile practices. Furthermore, the guide compares popular agile frameworks like Scrum, Kanban, and Extreme Programming, and outlines the roles and responsibilities of key team members in the agile ecosystem.