Cavity walls are made up of an outer wall (ie brick) and studs or concrete blocks inner supporting wall. The cavity in between (usually a minimum of an inch) is a space for air circulation and also...
A "Fresco."
No.
They act as a deflecter-so they deflect the energy and force of the sea and push it back out to sea they are a great form of coastal defence.
Not sure if this is what you are asking. Usually one is the oven, and one is the broiler, there just separated.