The term "prehistoric" literally means "before history." History is the time since people began to write things down, which was approximately 5,000 years ago in the Middle East. In other areas history began later. For example, in most of the Americas and Australia, history didn't begin until Europeans arrived in 1492 and the late 1700's respectively, because the locals didn't write yet.
Generally speaking, it is any time period before humans recorded events, i.e. "before history". You can see this or something similar in just about every dictionary definition.
That doesn't mean just "writing". Recording can be cave paintings or other 'non-verbal' recordings. Since we are continually discovering new evidence of man's distant past, that time period keeps getting pushed back -- there are cave paintings found in France that have been tested to be over 10,000 years old!
It is very interesting to me, however, that many of our recorded events are recordations of events that supposedly occurred beforehand and were passed down by word of mouth!
If you want a better timeline on earth's geologic history that includes some idea of when we began to record our events, here's an interesting site:
http://www.scientificpsychic.com/etc/timeline/timeline.html
Prehistoric means before recorded or written history.
the time before history was recorded
ancient, in the beginning
it is when people didn't writethe history
Primitive
before recorded history
Any time before the existence of coherent written records.
The duration of His Prehistoric Past is 600.0 seconds.
His Prehistoric Past was created on 1914-12-07.
The prehistoric past of the Philippines is researched in a similar manner to the prehistoric record of other countries. Archaeological digs uncovers artifacts and remains of prehistoric civilizations, revealing new details about their lives and practices.
The past tense of refer is referred.
Prehistoric time is time before history.
The Extinct Animal website (refer to the link, below) lists a number of prehistoric fish and reptiles.
Humans have used integers since prehistoric times and the situation prior to that time is not well understood.
The past tense of refer is referred.
Forms of life from the past, e.g dinosaurs.
Prehistoric is basically the time before recorded history.