What is grass-fed, grass-finished and pasture raised?

Grass-finished comes from animals that ate nothing but grass and forage for their entire lives. Grass-fed, on the other hand, may be used to label meat from animals that were started on a grass diet but have either received supplemental grain feed or are finished on a fully grain-based diet. Grass-fed does not mean that the animal spent any time in a pasture, they could have been fed hay in a feedlot. 100% grass fed is the same as grass finished and pasture raised.