Air handlers and furnaces aren't usually installed in the same home in Ocala. If you use a furnace, you most likely shouldn’t need to think about an air handler.
Air handlers are frequently paired with heat pumps and control airflow around your house. Some units also have secondary heating and cooling parts to help the heat pump.
A furnace runs in a different manner by blowing heated air into your vents, which move it across your residence. Because furnaces have combustion chambers to produce warmth, they don't use some of the pieces you'll see in a standard air handler.