The word "inscription" is usually used to mean something that is written or carved or printed on to something else. It is usually meant to commemorate some event. So we would not call all the stuff that is written in a book an "inscription." However, if you give someone a book for graduation or some other event like that and you write something like "To my best friend ever: don't forget me when you go off to college," that is an inscription.
Inscriptions are things that are often found and used by archaeologists. You could make any number of sentences about inscriptions that archaeologists might find. For example: "The archaeologists struggled to make sense of the inscription that they found on the tomb."
I plan to add an inscription in my husband's wedding ring.