Primary sources are directly from the event of what is being told. It is strictly first hand information. Secondary information is more passed on information from one another like a textbook and so forth, it is more likely to have certain information possibly slightly altered. Since history has always been an oral thing from person to person, this also causes oppertunity for change. Each person tells a story differently, which means that the story may have been altered in the sense of the way the storyteller wanted it to be heard.That is why you have to remember that many aspects have to be taken into consideration when valuing the truth of history.