Agile is a project management style that applies a cross-functional approach throughout the software development lifecycle (SDLC). Involving multiple methodologies, Agile describes a set of values and principles for software development under which requirements and solutions evolve through the collaborative effort of self-organizing cross-functional teams.
The Manifesto for Agile Software Development describes the central values and principles applied in an Agile approach. It is a popular evolution of more traditional project management styles, such as the waterfall model. It emphasizes cross-functional teams, communication, collaboration, and self-accountability rather than siloed, progressive teams. Agile allows teams to quickly and proactively respond to changes and problems. Two of the most popular Agile approaches adopted are Xp (eXtreme Programming) and Scrum.
To learn more about Agile, read our article, SAST Checklist for .Net and Agile Teams.