Vented hoods have a built in neoprene area at the top of the hood that allows for air to escape. The benefit of a vented neoprene hood is that if you are SCUBA diving air can get trapped in your hood and create extra space for water to pool in your hood. This can make your head cold and your body work harder to keep the water in your hood warm. Vented hoods are typically full length bibbed hoods.
There are different types of bibbed hoods to choose from. Some bibbed hoods have visors for surface water sports and other neoprene bibbed hoods do not have visors for underwater sports. It is common that bibbed hoods without visors can also be worn for surface sports such as surfing.