In Greek mythology, Pandora opened a jar, although later retellings call it a box.
Hesiod’s Greek word is pithos, a large storage jar used for commodities such as grain or oil. In Works and Days, Pandora removes the lid and releases the troubles kept inside. The story does not originally describe a small wooden box.
The “box” version became dominant through a Renaissance translation. The humanist Erasmus translated pithos into the Latin pyxis, meaning a small box or container, and that wording strongly influenced later European versions.
The distinction matters because “Pandora’s jar” is closer to Hesiod’s text, while “Pandora’s box” is the familiar modern expression. The myth also differs among retellings about whether hope remains inside after the other afflictions escape.