A primary source is a first-hand account of any information in the research. Primary sources are items that do not have conclusions based on a study, book or another source, state the fact of the matter based on first-hand experience and are close to the topic of study. There are primary sources in any type of research project, regardless of the topic or subject matter.
Secondary sources draw conclusions based on a primary source. These sources do not have first-hand knowledge and instead draw on the knowledge of primary sources for information. The secondary source is a common type of source in research projects because it is the easiest research item to find.
Primary sources vary widely depending on the type of research. Common sources include diaries or journals about the topic, newspaper or magazine articles if they were written at the time of the event or shortly after, government records, interviews with the participants in an event, songs, plays, poems, stories or works of art. Primary research sources can include the published results of an experiment or research of a scientist or scientific conferences with the expert.
A secondary source can include items like encyclopedias, biographies, history books, reviews of books, art and similar items. For a scientific study, the secondary sources can include an analysis of a clinical trial or a review of scientific results.