Definition of Kanban
Kanban is a strategy for optimizing flow (the stream of value). At its core is the process that uses a visual, work-in-progress (WIP) limiting pull system.
Kanban and Scrum are often used together. Scrum with Kanban does NOT change Scrum; it adds some great Kanban practices that make the work more visible.
These practices come from The Kanban Guide for Scrum Teams. They help to improve and complement the Scrum framework and its implementation.