Whats the difference between a fan coil unit and a air handling unit for HVAC ?

Fan-coil unit (FCU) 
A small terminal unit that is often composed of only a blower and a heating and/or cooling coil (heat exchanger), as is often used in hotels, condominiums, or apartments. 

For Fan coil units, our range include below catagories:

Air Handling Unit (AHU) 
Central unit consisting of a blower, heating and cooling elements, filter racks or chamber, dampers, humidifier, and other central equipment in direct contact with the airflow. This does not include the ductwork through the building.

For more info you can check at DEKON.