Central air conditioning (or central A/C) is an HVAC system in which air is cooled at a central location and distributed to and from rooms by one or more fans and ductwork. The work of the air conditioner compressor is what makes the whole process of air conditioning possible. This is one of the most common types of air conditioning systems.
SEER Rating: Seasonal Energy Efficiency Ratio, or the ratio of the cooling output of an AC system during a typical cooling season, divided by the energy it uses in Watt-Hours. Like miles-per-gallon in your car, the the higher the SEER Rating the more cooling comfort you get per dollar spent on energy.