Applied to cooking, this means to boil a liquid until its volume is reduced by evaporation. This thickens the liquid and intensifies the flavor. To submerge a cooked food, usually a vegetable, in cold water to cool it quickly and stop further cooking. It's also know as shocking. To cook fatty meats, such as bacon or spare ribs, until the fat melts.
Heat drives meat s juices from the surface when it cooks.
Letting meat rest before slicing lets these juices seep back towards the surface. The result is a more flavorful piece of meat. A cook's privilege. The cook does not have to allow anyone else to taste until the food is served.