In Hesiod’s Works and Days, Pandora actually opened a jar.
Hesiod’s Greek text describes a pithos, a large storage vessel used in the ancient Mediterranean. Such jars could hold grain, oil, wine, or other commodities, so the original image was not a small hinged container like the one common in modern artwork.
The word “box” became standard much later through translation history. The sixteenth-century humanist Erasmus rendered the vessel as a Latin pyxis, meaning a box or small container, helping establish the familiar phrase “Pandora’s box” in European languages.
This is one of the best-known differences between the ancient story and later retellings. The myth’s central idea remains the release of evils into the world, but the physical object changed in the cultural imagination. Some modern editions preserve “jar,” while others use “box” for familiarity.