It was invented in 1798. The 'litho-' part of the word means stone . The '-graph' part means writing . So lithograph means stone writing . A flat polished stone was used when lithography was first invented.
Modern lithography uses a printing master instead of a stone.
The printing master is si milar to a printing plate except it is made of thin flexible sheets of metal or fiber. A finished printing master is flat in appearance. It does not have a raised image as would a rubber stamp. It is flexible so it can be wrapped around a cylinder or drum that rotates. A printing master can be made by using photography.