Agile is a self-descriptive software development methodology. It is enshrined within the Agile Manifesto;
Manifesto for Agile Software Development
We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value:
Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan
That is, while there is value in the items on the right, we value the items on the left more.
... and its 12 supporting principles which collectively describe a philosophy differing from more traditional methods (e.g. waterfall) by putting emphasis on humanity, functionality and adaptability
Something can be described as 'agile' if it fits within the context of the manifesto and principles, such as a framework (e.g. Scrum), an event (e.g. a retrospective) or a tool (e.g. a Kanban board).
meta
Type: methodology Phase: Celebration, Dreaming, Planning, Doing Works well with: Incompatible with: Part of: Requires: Made easier with: