Oven "Broiler" Why is it a broiler with the same flame?

My gas oven had a broiler drawer under the oven. It was the bottom oven burner that was on, but it was above the food in the broiler drawer. The electric oven had a heating coil at the top that only heated if set on broil. Again, the heat from the top. I don't have an oven or broiler now, just a microwave and convection oven --- I do my chips & cheese in the microwave.