Walnuts are a type of tree nut that is native to the Middle East and Central Asia. They are oval-shaped and have a brown, textured outer shell that encloses a hard, woody inner shell. Inside the inner shell is the edible portion of the nut, which consists of two lobes that are covered in a thin, papery skin. Walnuts are known for their rich, buttery flavor and crunchy texture, which make them a popular ingredient in many dishes, including baked goods, salads, and main courses. They are also a good source of protein, fiber, and essential vitamins and minerals, such as vitamin E, magnesium, and phosphorus.