Air handlers and furnaces aren't usually used in the same home in Orlando. If you rely on a furnace, you probably shouldn’t need to spend time thinking about an air handler.
Air handlers are frequently paired with heat pumps and manage airflow around your home. Some models also offer extra heating and cooling components to support the heat pump.
A furnace heats in a different manner by pushing hot air into your vents, which circulate it around your house. Because furnaces have combustion chambers to produce heat, they don't have some of the parts you'll see in a regular air handler.