The purpose of all fire dampers is to completely block the passage of air through a duct or through a ceiling. There are three standard types of dampers:
Standard Fire Dampers are designed to operate with the HVAC system blower off during an alarm and they have a blade that is held open with a fusible link that melts during a fire, releasing the blade to drop shut with gravity.
Dynamic Fire Dampers are designed with springs to push the blade closed during a fire instead of using gravity.
Ceiling Radiation Dampers are not designed to block ductwork like Standard and Dynamic Fire Dampers but are specifically designed to limit the radiant heat transfer through an inlet or outlet of a fire rated ceiling.