The answer to 'central air or central air' is that they refer to the same type of HVAC system. Central air conditioning is a type of air conditioning system that cools an entire home or building using a single, centralized unit. This system consists of an outdoor compressor/condenser and an indoor air handler or evaporator coil that works together to circulate cool air throughout the home via a network of ducts.
Central air systems are highly efficient, provide even cooling throughout the home, and are often more cost-effective than window units or other types of cooling systems. They are a popular choice for many homeowners due to their convenience, reliability, and ability to maintain a comfortable indoor temperature year-round.