Generally, if you write while looking at a source or while looking at notes taken from a source, a footnote or reference should be given. We encourage students to explore, appreciate, and use the ideas of others, but we expect proper attribution of those ideas. Even when describing the arguments or opinions of others entirely in your own words, you must give credit to the original author. Paraphrasing is the expression of another writer's words and ideas. A primary source is a document or artifact written or created during the period you wish to study.
Secondary works are books or articles written after the fact.