What is the process called when heated air moves from baseboards heaters to the rest of the room?

Heat from baseboard heaters mostly move out into a room via Convection

Baseboard heaters take in cold air near the floor. The heater warms the cold air, making expand, thus it is lighter than the surrounding air. The surrounding cold air sinks and pushes the warm air up and away from the heater. The heater then warms that air. It's a cycle of warm and cold.

A small amount of transfer will also occur via "radiation" in a manner much like the heat of the sun moving to the earth. If you place your hand near some baseboard heaters you can actually feel the heat radiating from it without being within the flow of heated air coming off of the heater.