A heat pump is an air conditioner in the summer and a reverse air conditioner in the winter.
So, during the summer, the heat pump extracts heat from your indoor air making it cool, transfers the heat through the refrigerant and releases it to the outside. Have you ever felt the hot air blowing out of your outside condenser unit in the summer? A heat pump will look and feel just the same.
Now, in the winter, the heat pump takes that hot air and, instead of venting it to the outside, it pushes it into your home. The outside unit of a heat pump system works ALL year, not just in the summer like an air conditioner.
Since the outside unit is providing the hot air, a heat pump system does NOT have a furnace. Instead, it utilizes an air handler to circulate the air through your home.