There are many definitions for the word hybrid. For example, consumers associate hybrid automobiles with energy-saving efficiency, farmers associate hybrid corn with higher crop yields, and hybrids in biology involve crossbreeding species.
In HVAC, hybrids are often defined by the comfort level building occupants strive to achieve. In today's techno world, it is possible to combine equipment into an efficient system that raises the comfort level beyond normal means - and customers are showing a willingness to pay extra for indoor comfort. That comfort level is also accompanied by lower energy costs, making hybrid systems an attractive option for building and homeowners.