The ecosystem is a connected system of formal and informal learning (education and training) and work. The Learn & Work Ecosystem Library identifies 12 building blocks (key components) comprising the ecosystem. When all the building blocks are working together, individuals are able to move more seamlessly through the marketplace using a variety of credentials to communicate the skills and knowledge acquired in multiple settings (e.g., school, work, service, self-study). Employers have more detailed and externally validated information during their hiring and upskilling processes. Schools are better able to count learning obtained outside of academic settings toward a degree or other credential. And the public is informed about our learn-and-work ecosystem. For the ecosystem to function effectively, all parts of the system must be connected and coordinated.