Winter squash is a type of edible gourd that is typically grown during the fall and winter months. These types of squash have hard, thick shells that keep for several months, making them ideal for storing through the colder seasons. Some popular varieties include acorn squash, butternut squash, spaghetti squash, and pumpkin. Winter squash is often used in recipes or as a healthy side dish due to its high nutritional value, including being rich in vitamins A and C, fiber, potassium, and antioxidants.