The answer to 'difference between central air and' is that central air conditioning is a whole-home cooling system, while window or portable air conditioners are designed to cool individual rooms. Central air provides more consistent, efficient cooling by circulating cool air through a network of ducts, while window units are better suited for smaller spaces or homes without ductwork.
Central air systems have an outdoor compressor/condenser unit and an indoor air handler that distributes the cooled air. They are more expensive to install but can be more energy-efficient and provide better temperature control throughout the home. Window units are less expensive upfront, but may use more electricity and only cool the immediate area.