Primary Sources are immediate, first-hand accounts of a topic, from people who had a direct connection with it. Primary sources can include: Texts of laws and other original documents. Newspaper reports, by reporters who witnessed an event or who quote people who did.
In contrast, a secondary source of information is one that was created later by someone who did not experience first-hand or participate in the events or conditions you're researching. For the purposes of a historical research project, secondary sources are generally scholarly books and articles.