Original: The term '' prehistory '' can be used to refer to all time since the beginning of the universe , although the term is more often used to describe periods when there was life on Earth and even more commonly , to the time when human-like beings appear on Earth .
Simplified: Pre-history can start at the start of the universe but the word more often means a time when there was life on Earth ; dinosaurs are called prehistoric animals and cavemen are called prehistoric people .