The Greek vessel called Pandora’s “box” in Hesiod’s original story is a pithos. A pithos was a large ceramic storage jar used in ancient Greece for commodities such as grain, oil, or wine.
Hesiod’s Works and Days uses the Greek noun pithos, not a word meaning a small box. The familiar expression “Pandora’s box” developed later through translation and retelling, especially after the story entered Latin and Renaissance literary culture. The change made the image more compact and memorable in European languages.
This distinction matters because the physical object affects how the scene is imagined. A pithos could be substantial, sometimes large enough to store household supplies, whereas a modern box suggests a portable container with a lid. “Pandora’s jar” is therefore a closer rendering of Hesiod’s wording, although “Pandora’s box” is now the standard English phrase and the source of the idiom for an action that releases unforeseen problems.