What do we mean by Prehistoric?

Prehistory is history before humans invented writing. So there are no written records of this period. Historians get their evidence of this from archaeology and anthropology.

The earliest evidence of writing comes from about 5,000 years ago in Mesopotamia, man area including modern-day Iraq. However, we consider British prehistory to end with the arrival of the Romans.
Some people refer to any time before writing was invented as prehistoric which would include dinosaurs. However, many historians use the word prehistoric to refer to human history.

Non-avian dinosaurs died out in a mass extinction event around 66 million years ago. Although there is new evidence to suggest that our primate ancestors (part of the hominid family) may have briefly walked the earth the same time as dinosaurs.

Our Hominin ancestors, the Australopithecus started using tools around 3.3 million years ago.

The Homo genus only arrives around 2.8 million years ago.

Hopefully, we've not confused you too much!