A pie crust is a baked pastry shell that serves as the base for various types of pies, including fruit, custard, and savory fillings. It is typically made from a mixture of flour, fat (like butter or shortening), and water, which creates a flaky texture when baked. The dough is rolled out and placed in a pie dish, where it can be pre-baked or filled before baking. There are two main types of pie crusts: single crust, which covers only the bottom of the pie, and double crust, which has both a top and bottom layer. The choice of crust can affect the overall flavor and texture of the pie, making it an essential component in pie-making.