SEER, or the Seasonal Energy Efficiency Ratio, is a measure used to evaluate the efficiency of cooling systems, particularly air conditioners and heat pumps. It represents the cooling output during a typical cooling season divided by the total energy consumed in watt-hours. A higher SEER rating indicates a more energy-efficient system, which can lead to lower electricity bills and reduced environmental impact. The SEER rating is important for consumers when selecting HVAC systems, as it helps them compare different models. In many regions, there are minimum SEER requirements set by regulations to ensure that new units are energy-efficient, promoting sustainability and energy conservation.