All pumpkins and squash commonly grown in the vegetable garden or purchased in the grocery store and/or your local farmers market may be eaten, but there is a big difference among varieties, which are typically group by their most common usage:
Ornamental — Ornamentals are pumpkins and winter squashes which American children and patient parents carve just before Halloween, are grown with color, structural strength, a flat bottom, and a sturdy stem as their main attributes. Though most commonly used as decorations in the home and yard many of these squash make good eating, especially the smaller varieties which are frequently stuffed and baked or bake, then used as eatable soup bowls.
Culinary — Culinary pumpkins and winter squashes have firmer flesh and a sweeter taste and thus are used for cooking, pies, pickles, preserves, and savory dishes. There are many varieties of culinary pumpkins, and some heirloom varieties are highly prized for their taste and texture.
Competition – These pumpkins and winter squashes are grown mostly for their size, which can be really quite large 300 to 1,500 pounds are not unusual. While these varieties are eatable, their flesh is generally not as desirable for cooking and they are most frequently used for in competitions or as yard decorations.