How does air conditioner work?

It works on the same principle as that of refrigerators.

a refrigerant is made to circulate inside the room and absorbs all its heat and it vaporizes. the heat of this refrigerant is further increased after it is compressed in the compressor. after this it is sent to the condenser where it exchanges heat with its surroundings and thus its temperature falls again. after this it passes through the expansion valve where the vapor becomes liquid again and the cycle repeats itself.