Agile Software Development is a set of principles for software development under which requirements and solutions evolve through the collaborative effort of self-organizing and cross-functional teams. It advocates adaptive planning, evolutionary development, early delivery, and continual improvement, and it encourages flexible responses to change.

Principles

The Agile Manifesto, which was created by a group of software developers in 2001, outlines the key principles of Agile Software Development:

1. Individuals and interactions over processes and tools: Agile methodologies place a premium on effective communication and collaboration.

2. Working software over comprehensive documentation: Agile developers focus on delivering working software as quickly as possible and then improving it over multiple iterations.

3. Customer collaboration over contract negotiation: Agile development involves the customer in the development process to ensure the product meets their needs.

4. Responding to change over following a plan: Agile development is all about being able to respond to changes in the business environment or technology landscape.

Practices

Agile Software Development is not a methodology in itself, but it encompasses various methodologies and practices, including:

• Scrum: This is a framework that involves a set of practices for managing and incrementing a product’s development in a flexible and holistic manner. It's based on a sprint-based project timeline.

• Kanban: This is a visual system for managing work as it moves through a process. It visualizes both the process and the actual work passing through that process.

• Extreme Programming (XP): This methodology emphasizes customer satisfaction and promotes the delivery of high-quality software quickly and continuously.

Benefits

Agile Software Development offers several benefits:

• Flexibility and adaptivity: Agile teams can adapt to changes quickly and efficiently.

• Customer satisfaction: By involving the customer throughout the development process, Agile ensures that the end product meets the customer's needs and expectations.

• Risk management: Regular iterations allow for testing and review, ensuring that errors or issues are caught and dealt with early.