Not all pumpkins are the same. There are actually dozens of different varieties of pumpkin. They are split into winter and summer pumpkins, based on how long you can keep them.
Summer pumpkins are harvested soon after flowering, when the rind is soft and edible. This does mean they do not keep for long. The most common varieties are courgettes, pumpkin proper and pattypan squash.
In Belgium, the main winter pumpkins are giant pumpkins, spaghetti squash and ornamental gourds. The fruits are not harvested until they are completely ripe. Their thick, hard rind should not be eaten. This pumpkin is mostly used for decoration (Halloween).