What does Rosetta Stone mean?

Answer 1

A Rosetta Stone is a part of an inscribed granite stela that was originally about six feet tall and was set up in 196 BC; the inscriptions in hieroglyphics and Demotic and Greek gave the first clues to the decipherment of Egyptian hieroglyphics

Answer 2

Rosetta Stone is a rock discovered in 1799 upon which was inscribed with an ancient Egyptian decree written in three different languages. Two of the languages were written in hieroglyphics while the last one was written in ancient Greek. By comparing the hieroglyphics with the Greek version, scholars were able to decipher the hieroglyphics. The Rosetta Stone proved to be the key to understanding the previously undecipherable language.