A primary source is an original object or document-- the raw material or first-hand information, source material that is closest to what is being studied.
Primary source vary by discipline and can include historical and legal documents, eye witness accounts, results of an experiment, statistical data, pieces of creative writing, and art objects. In the natural and social sciences, the results of an experiment or study are typically found in scholarly articles or papers delivered at conferences, so those articles and papers that present the original results are considered primary sources.
A secondary source is something written about a primary source. Secondary sources include comments on, interpretations of, or discussions about the original material. Secondary source materials can be articles in newspapers or popular magazines, book or movie reviews, or articles found in scholarly journals that evaluate or criticize someone else's original research.
A tertiary source is a distillation and collection of primary and secondary sources.
Credits. See https://libguides.apsu.edu/primary_sources
The newspapers, pamphlets, and books gathered by the Reverend Charles Burney (1757-1817) represent the largest and most comprehensive collection of early English news media.
17th and 18th Century Nichols Newspapers Collection features London newspapers and pamphlets gathered by antiquarian and printer John Nichols. This collection, sourced from the Bodleian Library, spans the years 1672 to 1737 and complements the titles and issues found in 17th and 18th Century Burney Collection Newspapers.
Internet Library of Early Journals Digitized runs of important 18th and 19th century British journals
The Blake Archive