Primary Sources are original records created during the time period under study, or, after events occurred in the form of memoirs and oral histories. They reflect the individual viewpoint of a participant or observer and are often referred to as the raw data used by historians to interpret the past. Examples of primary sources would include diaries, letters, newspaper articles written at the time of an event, novels, poems, artifacts, original scientific experiments etc.
Secondary Sources are works that interpret or analyze historical events or phenomena. Secondary sources often base their theories or arguments on the direct evidence presented in primary sources. Examples of secondary sources would include criticisms or interpretations of literary works, books about historical events, textbooks, interpretations of scientific research etc.