In the Greek myth, Pandora’s original container is usually identified as a jar. Hesiod uses the ancient Greek word pithos, a large storage vessel commonly made from clay and used for commodities such as grain, oil, or wine.
The familiar phrase “Pandora’s box” developed later, after the Renaissance scholar and translator Erasmus used the Latin term pyxis, meaning a box or small container, in a Latin version of the story. That translation helped establish the modern expression.
The difference matters because the jar belongs to the earliest literary tradition, while the box belongs to the later popular wording. Both refer to the same mythic container, but “jar” is the more historically precise description of Hesiod’s vessel.