A croissant is a buttery flaky pastry named for its distinctive crescent shape. It is also sometimes called a crescent, from the French word for "crescent". Croissants are made of a leavened variant of puff pastry. The yeast dough is layered with butter, rolled and folded several times in succession, then rolled into a sheet, a technique called laminating.
Crescent-shaped food breads have been made since the Middle Ages, and crescent-shaped cakes (imitating the often-worshiped Moon) possibly since classical times, but the modern croissant dates to 19th-century Paris.
Croissants have long been a staple of French bakeries and pâtisseries. In the late 1970s, the development of factory-made, frozen, pre-formed but unbaked dough made them into a fast food which can be freshly baked by unskilled labor. Indeed, the croissanterie was explicitly a French response to American-style fast food, and today 30–40% of the croissants sold in French bakeries and patisseries are frozen.
This innovation, along with the croissant's versatility and distinctive shape, has made it the best-known type of French pastry in much of the world. Today, the croissant remains popular in a continental breakfast.