What Is Agile Methodology?
The Agile SDLC model is a mix of iterative and incremental process models focused on process adaptability and customer satisfaction through the rapid delivery of the product with working software. Usually, each iteration lasts from about one to four weeks.

Four Core Concept of Agile Methodology:

1. Interactions between individuals and teams over tools and procedures.
2. Working software on detailed documentation.
3. Customer cooperation in negotiating contracts.
4. Responding to change according to a project.

Agile manifesto:

1. Our highest priority is to please the client by providing useful applications early and consistently.
2. Welcome changing demands, even late in creation. Agile method harness adjustment for the strategic benefit of the customer
3. Deliver working applications regularly, with a preference for the shorter time scale, from a few weeks to a few months.
4. Throughout the project, business people and developers must work together daily.
5. Create projects around people who are inspired. Offer them the atmosphere and support their needs, and trust them to do the job.
6. Face-to-face conversation is the most powerful and productive way of communicating information to and inside a production team.
7. The important aspect of development is working software.
8. Agile methods encourage sustainable development. It should be possible for sponsors, developers, and users to maintain a steady speed indefinitely.
9. Agility is improved by a constant commitment to technological quality and good design.
10. It is important to have simplicity-the art of minimizing the amount of work not completed.
11. From self-organizing teams, the best architectures, specifications, and prototypes emerge.
12. The team focuses on how to become more productive at regular intervals, then tunes and modifies its actions accordingly.

Agile Methodology Example:
-->Scrum.
-->Extreme Programming (XP).
-->Dynamic Systems Development Method (DSDM).
-->Crystal Methods.
-->Feature-Driven Development (FDD).
-->Lean Development (LD).
-->Adaptive Software Development (ASD).