A stockade is a fortification or enclosure for prisoners made of upright timbers or posts driven into the ground. Stocks are a restraint that immobilize the limbs, while a pillory also immobilizes the neck and/or torso.
bvgtynkgb said: Stocks restrain only the legs and force the victim to lie on the ground.
Stocks might restrain any limbs, but only limbs. For instance, this kind of restraint restraining only the wrists are also stocks, and need not necessarily force a particular posture.