In this LANDFIRE Office Hour, Dr. Ayn Shlisky Hunt and Ray Brunner compare four national ecosystem classification systems: the Terrestrial Ecological Unit Inventory, LANDFIRE, the U.S. National Vegetation Classification, and ecological sites. Learn how these systems differ in purpose and approach, where they overlap, and what land managers, researchers, and policy makers should know about their strengths and limitations. The discussion considers practical opportunities to use the classifications together and draw from what each does best.