Wood, propane, or natural gas is typically used to heat a pizza oven. During the heating process, the dome, sides, and cooking surface of the oven gets extremely hot from the fire source and soaks up the high heat.
A brick pizza oven will retain more heat than a metal pizza oven and will also hold heat longer. Unlike a charcoal grill, once the desired temperature is reached, you can use conduction, radiant heat, and convection cooking interchangeably to cook in your pizza oven because the heat source is coming from all directions.