A pie is a baked dish with a crust and a filling, typically served as a dessert but sometimes as a main course. The crust forms a shell made from flour, butter, and water, rolled flat and shaped into a pan. Inside, you might find sweet fillings like apple, cherry, or pumpkin, or savory fillings like chicken and vegetables.

Pies have been around for centuries. Medieval bakers made enormous pies filled with meat, and early American settlers became well known for their fruit pies, using whatever grew locally. Today, phrases like easy as pie (meaning very simple) and pie in the sky (an unrealistic dream) show how common pies are in everyday language.

Different cultures have their own versions: British people enjoy meat pies and shepherd's pie (though that's technically not a true pie since it has mashed potato instead of a crust on top). Americans are known for pumpkin pie at Thanksgiving and apple pie year-round. When someone wants their fair portion of something, they might ask for their piece of the pie or their slice of the pie.

The mathematical symbol π (pi) is pronounced the same way but refers to the ratio of a circle's circumference to its diameter, approximately 3.14159.