The Rosetta Stone is significant because it provided the key to understanding Egyptian hieroglyphics. Discovered in 1799 during Napoleon's campaign in Egypt, the stone features the same text inscribed in three scripts: Greek, Demotic, and hieroglyphics. Scholars, particularly Jean-François Champollion, used the Greek text to decipher the hieroglyphs, which had been a mystery for centuries. This breakthrough not only unlocked the language of ancient Egypt but also opened up a wealth of knowledge about its culture, administration, and history, allowing historians to reinterpret thousands of years of Egyptian civilization.