Second: history. We tend to think about history as all of the stuff that has happened in the past. But if you want to be kind of strict about it, there’s a more specific word for stuff that happened before people began writing things down, and that word is prehistory. You see, when people began to write things down, they then had a way of documenting events as they actually happened. People could write: okay, this thing happened on this date, and that thing happened on that date. And so, now, even if we lived in a much later time than they did, we know about those people and what they did and what happened to them because of those records that they kept. Whereas there are no records of those things that happened before people began writing, so we have to figure out what happened then by piecing together different clues. For example, if an animal bone is found to be 709,000 years old, and that same bone bears marks of the tools used to cut up the animal, then we can safely say that, well, somebody must have been holding those tools, so there must have been somebody here – somebody with the ability to make tools and use them – 709,000 years ago. It’s a reasonable conclusion but it’s not as airtight as it would have been if there had been written records about it; that’s why we distinguish between recorded history and unrecorded history. So, again, everything that happened before people developed systems of writing is known as prehistory.