An information source is anywhere that data, facts, or evidence is provided about a specific topic. The types or classifications of sources are based on originality or proximity to the original source.

1. Primary sources are firsthand accounts of evidence or events. This would include raw data from interviews, surveys, or focus groups, letters, manuscripts, diaries, journals, newspapers, speeches, memoirs, documents from government agencies, photographs, audio and video recordings, and research data.

2. Secondary sources are ones that analyze, synthesize, evaluate, and interpret the primary sources. These sources can include literature reviews, biographies, and analysis of previous works.

3. Tertiary sources are ones that provide overviews or summarize a breadth of information. This might include almanacs, directories, and some textbooks.

For example, an original journal article would be a primary source, a literature review of the article would be a secondary source, and a textbook that references the article as a consulted source would be a tertiary source. 

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