Primary sources are "materials produced by people or groups directly involved in the event or topic under consideration, either as participants or as witnesses...Some primary sources are written documents, such as letters; diaries; newspapers and magazine articles; speeches; autobiographies; treatises; census data; and marriage, birth, and death registers" (Rampolla, 2012).
Secondary sources, then, are "texts - such as books, articles, or documentary films - that are written or created by people who were not eyewitnesses to the events or period in question; instead, the authors of secondary sources synthesize, analyze, and interpret primary sources..." (Rampolla, 2012).
A library catalog lists the resources in the library's collections--including interlibrary loan holdings. You can search for information by author, title, subject, and keyword.
Bibliographies and indexes are essentially specialized catalogs that helps searchers find specialized material, e.g. from a specific field (MLA International Bibliography), format (US Newsstream for newspapers), or particular publication (e.g. Wall Street Journal Index).