A croissant is a buttery, flaky, viennoiserie pastry of Austrian origin,
but mostly associated with France. Croissants are named for its
historical crescent shape and, like other viennoiserie, are made of a
layered yeast-leavened dough. The dough is layered with butter, rolled
and folded several times in succession, then rolled into a thin sheet,
in a technique called laminating. The process results in a layered,
flaky texture, similar to a puff pastry.
Crescent-shaped breads have been made since the Renaissance, and
crescent-shaped cakes possibly since antiquity. Croissants have long
been a staple of Austrian, Italian, and French bakeries and pâtisseries.
The modern croissant was developed in the early 20th century. In the
late 1970s, the development of factory-made, frozen, pre-formed but
unbaked dough made them into a fast food that can be freshly baked by
unskilled labor. The croissant bakery, notably the La Croissanterie
chain, was a French response to American-style fast food, and as of
2008, 30–40% of the croissants sold in French bakeries and patisseries
were baked from frozen dough.
-Wikipedia