An acorn squash is a type of winter squash with a distinctive acorn-like shape and a dark green or orange skin. It typically has sweet and nutty flesh that becomes tender when cooked. Acorn squash is commonly baked, roasted, or steamed and can be stuffed with savory fillings or simply seasoned and enjoyed as a side dish. It is rich in vitamins, minerals, and dietary fiber, making it a nutritious addition to meals.