Primary sources were either created during the time period being studied or were created at a later date by a participant in the events being studied (as in the case of memoirs). A primary source is either first-hand testimony or direct evidence about a topic under investigation.
They reflect the individual viewpoint of a participant or observer. Primary sources enable the researcher to get as close as possible to what actually happened during an historical event or time period
A secondary source is a work that interprets or analyzes an historical event or phenomenon. It is generally at least one step removed from the event and is often based on primary sources.
Examples include: scholarly or popular books and articles, reference books, and textbooks.