The answer is both. Refrigerant is both a liquid and a gas (vapor) depending upon where it is within the cooling cycle. The refrigerant is a low pressure, low temperature gas when entering your compressor. The compressor boosts the pressure up significantly and is pumped through the condenser where it is “condensed” from a high-pressure gas to a high-pressure liquid. This liquid refrigerant is then pumped to the indoor coil section of the AC system. There the liquid refrigerant goes through a device that drops the pressure significantly while it maintains a liquid state. At this point the refrigerant temperature drops from about 105 degrees to 45 degrees. This liquid state refrigerant is then pumped through the indoor coil where it absorbs heat from the house (hence cooling the air) which causes the refrigerant to boil, changing back from a liquid to a vapor. The process is then repeated by returning the gas back to the compressor.