The Agile approach defines a way of uncovering requirements through the collaborative effort of cross-functional, self-directed teams and customers. It is derived from frameworks such as Scrum, Kanban, Crystal, Extreme Programming and similar. This is why Scrum is considered an agile framework and associated with the Agile approach.
The Agile Manifesto states that individuals and their interactions are more important than processes and tools. Having well-established processes and using appropriate tools is important, but it is even more important to have talented and determined people working together for a common purpose.
Working software is more important than extensive documentation. Documentation is useful when used with care, but it should not be the focus.
Collaboration with the customer is more important than contract negotiations. Building trust and having a working relationship where both parties help move forward will add value to the project.
It is important to be able to adapt to change rather than following a plan. Be prepared to make changes to the plan as needed. The more flexible you are, the better.
The ideas and principles of the Agile Manifesto apply not only to software development, but also to other product categories. Scrum existed before the Agile Manifesto was created in 2001. Ken Schwaber and Jeff Sutherland are known as the creators, promoters, and maintainers of what has since become the Scrum framework.