Grilling is a method of cooking food by concentration under very high heat. The grilling process, which usually begins with a hot grill and a tender food item, sears the item and locks in the juices by forming a dry surface crust (with meat, it is the coagulation of the proteins on the surface). With the exception of grilled vegetables, which can be served at room temperature, grilled items are cooked to order and served immediately.
The relationship between the surface sear and the interior doneness is the key to great grilling. It is, therefore, extremely important to learn how to judge the heat of the grill, its hottest and coolest areas, as well as to understand the degree of grilling necessary in relationship to the size, shape, and texture of the food. Like many kitchen skills, this is best done over time through trial and error and lots of practice.