Prehistory is the study of extinct non-literate societies, existing before the local advent of writing systems.
Archaeologists also concern themselves with literate societies of the past.
Classical archaeologists study civilizations of the ancient Near East, such as ancient Egypt, and those of the Mediterranean Basin, such as ancient Greek and Roman empires. The choice of where to dig is governed by the questions the archaeologist is trying to answer. In short, archaeology is partly a field science, and partly a laboratory science. But in being a science, it also shares much with the humanities, in that it attempts to gain insights into the histories and lifeways of vanished human societies.