In Greek mythology, the storage jar associated with Pandora is called a pithos. The term identifies the large ceramic vessel described in the ancient tradition.
The pithos was a practical container in Greek life, often used for storing agricultural products. Ancient examples could be very large and were sometimes partly buried in the ground for stability and coolness. That everyday object became the container at the center of Pandora’s story.
The word is important because the English title “Pandora’s box” is not a literal reflection of Hesiod’s wording. The Latin scholar Erasmus helped popularize the box interpretation when translating the Greek term into Latin as pyxis, a word associated with a box or container.
This does not mean that modern retellings are invalid. “Pandora’s box” is now the established English expression. However, pithos is the more precise answer when the question concerns the vessel in the earliest surviving literary version of the myth.