Primary Source: A source, whether it be a document or record that is created during the time of the topic being researched. Or created later by an observer of that event. It contains original and raw data.
Secondary Source: A source created by interpreting and analyzing primary sources. Usually, one step removed from the primary source.
Tertiary Source: Encyclopedias, dictionaries, textbooks, and sources that give broad overviews of the topic.
Government Documents: Published by the Federal or State governments and held in official depositories.