Inscriptions are written on hard surfaces. Many were written several hundreds of years ago. All inscriptions contain both scripts and languages. Languages which were used, as well as script have changed over time. Scholars understand the written words by the process of decipherment.
One of the most famous stories of decipherment comes from Egypt where there were kings and queens about 5000 years ago. An inscribed stone was found in Rosetta, which contained inscriptions in three different languages. Scholars were able to read the inscriptions by identifying the sounds for which the Egyptian letter stood. Eg. Lion stood for L, and a bird for A.