Crusts are the outermost layer of the Earth, forming a thin shell around the planet's interior. They are primarily composed of rocks and minerals and vary in thickness, being thicker under continents and thinner under oceans. The Earth's crust is divided into two main types: the continental crust, which is thicker and less dense, and the oceanic crust, which is thinner and denser. In addition to the Earth's crust, the term "crust" can also refer to the outer layer of baked goods, such as bread or pizza. This crust is typically crispy and golden brown, providing texture and flavor to the dish. Crusts can be made from various ingredients, including flour, water, and fats.