Encampment Training is a project in Civilization VI. It becomes available after building an Encampment district (or one of its replacements).
While this project is underway, the city lends its production facilities to large-scale army drills, converting 15% of its Production output to Gold (maybe due to increased trade from army retainers). When completed, it yields Great General points equal to approximately 22% of the Production invested in it (on Standard speed).