Primary sources are accounts of events written by people who experienced them or lived at the time they happened. They are often but not always eyewitness accounts; a diary that mentions an event that the writer heard about but did not witness would also be a primary source, for example.
Secondary sources are things like scholarly articles or magazine articles that analyze or interpret historical events. A secondary source might refer to or cite primary sources, but it is never written at the same time as the event that it discusses.
