In the earliest surviving account of Pandora’s myth, Pandora opens a jar rather than a box.
The Greek word used by Hesiod is pithos, a large storage container commonly made from clay. Such jars could hold agricultural goods, liquids, or other materials, and they were familiar objects in the ancient Mediterranean world. Hesiod’s Works and Days says that Pandora lifted the lid and released troubles into the human world.
The “box” version became dominant through later translation history. In the sixteenth century, the humanist Erasmus rendered the Greek container as a Latin pyxis, a small box or casket. That wording helped establish the expression “Pandora’s box” in European languages.
The jar-and-box distinction is one of the most common facts people get wrong about the myth. The modern phrase is now standard, but the Greek original is better represented by “Pandora’s jar.”