"Primary sources are the raw materials of history — original documents and objects which were created at the time under study. They are different from secondary sources, accounts or interpretations of events created by someone without firsthand experience." (Library of Congress)
For more detailed explanations with examples:
Links users to resources in libraries, museums archives across the U.S. All of the materials found through DPLA—photographs, books, maps, news footage, oral histories, personal letters, museum objects, artwork, government documents, and so much more—are free and immediately available in digital format.Internet Archive
Created to offer permanent access for researchers and the general public to historical collections that exist in digital format.
Internet Archive : Moving Image Archive
Part of the larger Internet Archive, this is a collection of thousands of movies, films, and videos, ranging from classic full-length movies, to television news broadcasts, to historical film clips.
History Channel : Speeches
Contains hundreds of speeches that can be searched by speaker, subject or time period.
East Asia History SourcebookCold War International History Project
Housed at Fordham University, this is a collection of public domain and copy-permitted historical texts presented for educational use.
The American Presidency Project
The American Presidency Project is the only online resource that has consolidated, coded, and organized into a single searchable database The Messages and Papers of the Presidents: Washington - Taft (1789-1913), The Public Papers of the Presidents: Hoover to Bush (1929-1993), The Weekly Compilation of Presidential Documents: Clinton - Obama (1993-2009). The archive also contain thousands of other documents such as party platforms, candidates' remarks, Statements of Administration Policy, documents released by the Office of the Press Secretary, and election debates.