A combi oven can cook with circulating dry heat, steam, or a controlled combination of the two. Humidity control helps operators manage moisture loss, browning and reheating; available settings depend on the model.
It is different from a conventional convection oven with a pan of water added. Follow the equipment's loading and maintenance instructions and verify food temperatures independently when needed. A steam setting alone does not establish that food has reached a safe internal temperature.
Reference: Further reading.