Brief history of agile (from Atlassian)

History

Agile project management is an iterative approach to managing software development projects that focuses on continuous releases and incorporating customer feedback with every iteration.

Stemming from Toyota's lean manufacturing concept of the 1940s, software development teams have embraced agile methodologies to reduce waste and increase transparency while quickly addressing their customers' ever-changing needs. A stark change from waterfall project management that focuses on "big bang" launches, agile helps software teams collaborate better and innovate faster than ever before. 

Traditional agile project management can be categorized into two frameworks: scrum and kanban. While scrum is focused on fixed-length project iterations, kanban is focused on continuous releases. Upon completion, the team immediately moves on to the next. 

https://www.atlassian.com/agile/project-management