These terms relate to the variable refrigerant flow (VRF) or variable refrigerant volume (VRV) of systems. These systems offer alternatives to conventional residential and light commercial systems and have advantages and disadvantages over conventional systems (also known as 5 ton and under and often made by Carrier and other brands). These makers are now offering VRF/V systems as well.
The Advantages of a VRF/VRV System
The Disadvantages of a VRF/VRV System