Heat pumps are a type of HVAC (heating, ventilation, and air conditioning) technology that moves heat from one location to another. They work by transferring heat from a source (such as the air or the ground) and using that heat to warm a building in the winter or cool it in the summer. Unlike traditional heating and cooling systems, which generate heat or cold through the use of fossil fuels or electricity, heat pumps simply move heat from one place to another. They're a highly efficient way to heat and cool buildings, with some models having a Coefficient of Performance (COP) of up to 4, meaning they can provide up to four times the amount of heat or cooling energy compared to the amount of energy they consume.