What is "confectioners' sugar"?

Confectioners' sugar, also known as powdered sugar or icing sugar, is a finely ground sugar that has been processed into a powdery consistency. It is commonly used in baking and confectionery to sweeten and decorate various desserts, such as cakes, cookies, and pastries. Confectioners' sugar is made by grinding granulated sugar into a fine powder, and sometimes a small amount of cornstarch is added to prevent clumping. This results in a smooth, easily dissolvable sugar that is ideal for making icings, frostings, and glazes, as well as for dusting over baked goods to add a decorative touch.