Some models offer the opportunity to cook in different methods.
For example, the Outdoorchef models have inside a cone that according to its position can propagate the flame, and the relative heat directly on your food, or indirectly, reversing the position of the aforementioned cone, keeping the lid closed in such a way that the heat spreads uniformly inside the cooking chamber so that your dishes are heat wrapped uniformly in every point.
You can adjust the intensity of the flame according to the cooking needs of each specific food to always have an optimal cooking.
The main advantage of the gas barbecue is that it is easy to turn on, there is no need to have coal bags, nor to start preparing the barbecue in advance. When the food is cooked, the cook simply switches off the burners and closes the lid. There is very little else to do because generally the fat drips into an easy-to-clean container.
The barbecues can have a grill or a plate as a cooking surface, which can in turn be made of cast iron or lava stone.
Each method will have its advantages and disadvantages. Some larger models have the possibility of having both cooking surfaces.
The gas barbecues often have shelves on their sides to support your food and the necessary to cook, otherwise they can be enriched for example with a stove or with a fryer, to have always available multiple cooking methods.