A primary source is an original document/image, the results of an experiment, statistical data, first-hand account, or creative work. A secondary source is something written about or using primary sources.
|The text of The Gettysburg Address||An analysis of The Gettysburg Address|
|Census data for Detroit||A book about demographic changes in Detroit|
|A McDonald's commerical||A documentary about McDonald's advertising|
|The results of an experiment or clinical trial||An overview of different treatments options|
|An interview with a World War II veteran||A history book about World War II|