Hesiod describes Pandora opening a jar in Works and Days. The ancient Greek word is pithos, a large storage vessel typically used for commodities such as grain, oil, or wine.
The familiar expression “Pandora’s box” developed later because Renaissance translators rendered the Greek vessel as a box or container. The wording became especially influential after the sixteenth century, and the box image eventually replaced the large jar in popular culture. The original pithos is therefore an important distinction between the ancient text and the modern phrase.
The jar is not presented as a small decorative object in Hesiod’s poem. Pandora opens it after receiving it as part of Zeus’s plan, and evils escape into the human world. Hope remains inside in the poem’s difficult final detail, whose meaning has been debated by interpreters. The jar-versus-box distinction is one of the best-known examples of translation shaping mythology.