Pandora kept the jar closed until curiosity led her to open it in the myth associated with Pandora’s Box.
The familiar phrase “Pandora’s box” is based on a translation and later retelling of the Greek word pithos, which means a large storage jar. Hesiod’s earliest surviving account does not describe a small box. The jar contains destructive forces that escape when Pandora opens it.
The story became widely known in European culture through later Latin and vernacular traditions. A mistranslation or reinterpretation helped turn the large earthenware vessel into the compact “box” of the modern expression. The difference is important because the original container was a practical ancient storage vessel, not a specially crafted puzzle box.
The jar question is distinct from asking what escaped or what remained inside. In the traditional story, Pandora opens the container and the troubles spread into the human world.