You'll sometimes see historians or hear history teachers talk about Primary or Secondary sources. What do those mean?
Primary Sources - Sources written at the time a historical event occurred that describe it from the perspective of someone who was there when it happened, or who was effected by it in some way. Firsthand accounts, in other words.
Examples of primary sources:
The diary of a sailor who survived the attack on Pearl Harbor
Written testimony from a survivor of the Triangle Shirtwaist Factory fire
The transcribed oral account from a survivor of the massacre at Wounded Knee
Secondary Sources - Sources written by contemporary scholars or historians about an event that happened in the past. A secondary source will often refer to primary sources, but the author is not providing a firsthand account, but rather interpreting the firsthand accounts he or she refers to in order to offer an explanation or idea of why the event happened or what it meant to people who lived at the time.
Examples of secondary sources:
A book about Native American history
A paper published in a journal about the Black Death
A TV documentary about Alexander the Great