Rosetta Stone

The Rosetta Stone is a stone slab discovered in the Earth nation of Egypt. It is a damaged but partly legible decree containing text in two languages: Ancient Egyptian in both hieroglyphics and demotic script, and Ancient Greek. For Human linguists, the Rosetta Stone provided the key information for understanding ancient Egyptian text, and as such, 'Rosetta Stone' has since become a Human colloquialism meaning 'the key to understanding a subject'.