The primary source or original source is an, artifact, document, recording, or other source of information that was created during the under study ( time that the event had happened). Is it the first source of information about that topic.
A primary source is a source of information from the actual event. For example, the autobiography of Ben Franklin (if he did write one) would be a primary source. A biography of Abe Lincoln would be a secondary source because it didn't come from the actual event/person. (Fact: Abe Lincoln is the person who has the most books written about him in the world)