Both ACs and heat pumps look exactly the same. Turn on the heat and check the outside unit. Look at the labels on the condenser/indoor air handler labels. Check your condenser for a reversing valve.

Since heat pumps provide both cooling and heating, they are rated according to how efficiently they cool (SEER) and how efficient they heat (HSPF) If you see 2 numbers, one for a “Seasonal Energy Efficiency Ratio” and one for “Heating Seasonal Performance Factor”, then you have a heat pump.

A heat pump has a reversing valve, a part responsible for reversing the flow of refrigerant. If you see a brass-looking device with 3 fittings on one side, you have a heat pump.