False. Crumb is not a type of pie crust, but rather a type of topping that can be used on pies. A crumb topping is typically made from a mixture of flour, sugar, and butter that is crumbled together and sprinkled over the top of a fruit or custard pie before baking. Pie crust, on the other hand, is the pastry shell that forms the base and sides of the pie. It is typically made from flour, fat (such as butter or shortening), water, and sometimes sugar and salt.