In the beginning, in ancient Egypt, over 5000 years ago, scribes wrote things down using pictures. That was a scribe's job, to write things down. Scribes used a system of pictures to do so. These pictures were called hieroglyphics. It was beautiful art. Each symbol had a meaning. But it took time to write things down using hieroglyphics. The scribes needed a faster way to write, because the ancient Egyptians loved to write things down. The scribes created a new written language called Demotic script.
Many years later, when archaeologists discovered hieroglyphic writing on the walls of tombs, they could not read it. They knew the pictures had meaning. But the best they could do was to guess what those pictures meant.
One day, about 200 years ago, someone found a stone in ancient Egypt, a very old stone. There was some writing on the stone. It was a very short story. The same story was written in Greek, in Demotic script, and again in hieroglyphics. Scientists could read Greek. They could even read Demotic script. And now they could read hieroglyphics!
This stone was named the Rosetta Stone. The Rosetta Stone is currently on display at the British Museum in London, England.