In scholarship, a secondary source is a document or recording that relates or discusses information originally presented elsewhere. A secondary source contrasts with a primary source, which is an original source of the information being discussed; a primary source can be a person with direct knowledge of a situation, or a document created by such a person.
A primary source is stuf like an autobiography, and interviews. Info that is gathered straight from the person. Secondary source is something like a biography where the info is gather from a source other than the subject