Generally, squash are divided into two categories: summer squash and winter squash. Winter sqaush have hard, thick skins and seeds. They have deep yellow to orange flesh that is firmer than that of summer squash, thus requiring longer cooking. Winter squash varieties include butternut, hubbard, buttercup, acorn, spaghetti, kabocha, pumpkin and turban. Though most varieties are available year-round, winter squash is best from early fall through winter.
When selecting winter squash, choose one that is heavy and hard with a deep-colored rind free of blemishes. The hard skin of a winter squash protects the flesh and allows it to be stored for longer periods.