What does "reduce" mean in a cooking context?

In a cooking context, "reduce" specifically refers to the process of decreasing the volume of a liquid through simmering or boiling. This technique is often employed to concentrate the flavors of sauces, stocks, or soups. When a liquid is heated, water evaporates, which not only thickens the mixture but also intensifies its taste components, leading to a richer, more robust flavor profile. This method is commonly used in professional kitchens to enhance the overall quality of dishes, making the flavors more pronounced and layered, which is particularly important in fine dining and gourmet cooking.