Definitions of research related terms:
Catalog: List of library owned or accessible materials.
Database: Searchable collection of data and information often organized by content or subject type.
Peer-review: Articles written by professionals in the field and read by experts before publication in scholarly journals.
Primary source: Material created at the time of an event by someone who was there. Examples: letters, diary entries, photographs, video, interviews, news reports, etc.
Secondary source: Material created after an event using and analyzing primary sources or discussing non-original work. Examples: books, articles, essays, documentaries, etc.