Some of these resources represent digitized archival materials from specific institutions; others are portals to multiple institutions' digital collections or databases collocating digital archival materials on a given topic. These collections include some formats highlighted elsewhere in this guide, including newspapers, government documents, and books; in addition, they contain manuscript materials (e.g. letters, notes, drafts of publications), photographs, and more. Archives are rarely able to digitize the entirety of their holdings or the entirety of a given collection; you should look to see full descriptions of collections on an institutions' website to get more context for digitized archival materials.