In Greek mythology, Pandora opened a jar, not a box.
The earliest surviving Greek account appears in Hesiod’s Works and Days, where the container is called a pithos. A pithos was a large storage jar used in the ancient Greek world, commonly for grain, oil, or wine. The story says that Pandora opened it and released troubles into the world, while hope remained inside.
The familiar phrase “Pandora’s box” arose later through translation history. The Greek word pithos was rendered into Latin as pyxis, meaning a small box, in a sixteenth-century version associated with Erasmus. That wording became standard in many European languages and displaced the original image of a large jar.
The jar-versus-box distinction is therefore a common mythological mix-up. Both names refer to the same story, but “jar” is the more accurate answer for Hesiod’s original account.