Heat pumps and air conditioners both work off of the refrigeration cycle. A heat pump is essentially an air conditioner that has a reversing valve to allow the refrigerant to flow the opposite way.

I mean, a refrigerator uses a heat pump to cool itself. An air conditioner is a heat pump, it's just moving heat from inside to out instead of outside to in. It's specialized for it's purpose ofc, I doubt you could just install a window mounted air conditioner backwards and have an efficient heating solution, but they're atill using the same core process, just turned around

Sorry to umm akshually you