In Greek mythology, the original container holding Pandora’s troubles was a jar. The Greek word *pithos* referred to a large storage vessel, often used for commodities such as grain, oil, or wine.
The phrase “Pandora’s box” became popular much later because of a Renaissance translation. The humanist Desiderius Erasmus rendered the Greek vessel as a box or container in Latin, helping establish the wording now familiar in English and many other languages.
Hesiod’s account does not describe Pandora opening a small box in the modern decorative sense. The vessel’s size and practical use are important because the myth concerns a household object becoming the source of suffering in the human world.
The modern phrase still preserves the myth’s central idea: one action can release a chain of unforeseen problems. “Opening Pandora’s box” is now used for discovering complications, even outside mythological discussions.