The oven is to form hot air to bake cooking food a device, generally closed or semi-closed structure. Roasters are also known as ovens, ovens, ovens, open form of heating with hot air is called barbecue. Grill can also be used to refer to a device that uses hot air for high-temperature treatment. Traditional ovens are heated by burning wood and coal. Modern oven is multi-functional, the use of electric heat or natural gas, respectively, the oven is divided into single, double and triple layer type, each layer is independently controlled, can be used at the same time, but also a single layer of a single oven is divided into a single layer, double and triple layer type, each layer is independently controlled, generally have an automatic thermostat system.