Air handlers and furnaces aren't typically used in the same home in Fort Lauderdale. If you use a furnace, you most likely won’t need to spend time thinking about an air handler.
Air handlers are usually paired with heat pumps and manage airflow around your house. Some units also have extra heating and cooling components to help the heat pump.
A furnace works differently by sending hot air into your vents, which move it throughout your home. Because furnaces depend on combustion chambers to make hot air, they don't use some of the parts you'll find in a regular air handler.