In the original Greek myth, Pandora released evils from her container.
Hesiod’s Works and Days says that Pandora lifted the lid of a storage vessel, allowing destructive troubles to escape into the world. The text describes diseases and other hardships spreading among humans. These evils had previously been kept away from mortal life, so the opening of the vessel explains why people experience suffering.
The familiar English phrase “Pandora’s box” is a later development. Hesiod described a pithos, a large jar or storage vessel, rather than a small box. The Latin writer Erasmus helped popularize the “box” wording in the sixteenth century, probably through a translation choice involving the Greek term.
The myth does not say that Pandora released monsters or physical objects such as jewels. Its central contents are personified or imagined evils. The surviving account also gives the story a second, more hopeful element: one remaining thing stayed inside the vessel.