When you conduct research for a paper, you use many different sources. A primary source may be a letter, a diary, an interview, a speech, a law, a photograph, or a newspaper article written at the time of the event. A primary source provides firsthand information about an event from the perspective of someone who was present when that event occurred. A secondary source, such as an encyclopedia, a textbook, a biography or a research article, is a collection and interpretation of information gathered from other sources after the event has happened. If you look at the last page of an encyclopedia entry or a research paper, you may see a list of articles and books that the author consulted. By understanding the difference between primary and secondary sources, you can use the right information to support your research and draw accurate conclusions.