In Greek mythology, Hesiod described a pithos rather than a box as Pandora’s vessel.
A pithos was a large Greek storage jar, commonly used for commodities such as grain, oil, or wine. Hesiod’s Works and Days uses the Greek word pithos when describing the container associated with Pandora. The object was therefore much closer to a substantial household storage jar than to the small hinged box familiar from modern illustrations.
The phrase “Pandora’s box” developed through later retellings and translation history. The Latin writer Erasmus helped popularize the box formulation in the sixteenth century, and that wording became deeply established in European languages.
This distinction does not change the central action of the myth: Pandora opens the container, troubles spread into the world, and hope remains inside. It does explain why ancient art and modern popular culture can depict the object very differently.