Air handlers and furnaces aren't often used together in Fort Wayne. If you have a furnace, you most likely don't need to spend time thinking about an air handler.
Air handlers are typically paired with heat pumps and deliver airflow around your home. Some models also provide secondary heating and cooling parts to assist the heat pump.
A furnace heats differently by sending heated air into your vents, which circulate it throughout your residence. As furnaces use combustion chambers to make hot air, they don't use some of the parts you'll see in a standard air handler.