Kanban is a lean project management system that uses visual cards or boards to manage work. It originated from Toyota in the 1940s and focuses on limiting work-in-progress to improve flow and productivity. A Kanban board visualizes tasks, resources, and workflow to simplify communication. Tasks are pulled into stages based on available capacity rather than being pushed based on schedules. The process involves mapping workflows, limiting work-in-progress, focusing on continuous flow, and continuously improving based on metrics.