Primary Literature: 
Primary literature for scientists means this is the first publication of original research in journals, conference proceedings, magazines, and other sources.  Primary literature is the original work on which other works are based and usually shares new knowledge, findings, or results in its original form without interpretation by other writers.   Expect to see the following sections:

• Methods (population, materials. instruments)
• Results (with charts, graphs, etc.)
• Discussion

The abstract will probably include a phrase like “in this study” or something similar.  Articles will be very scholarly and appear in academic journals.

Secondary Literature:

Are the works based on primary literature that usually include interpretation or commentary by other writers or scholars not involved in the original research.  Reviews of Literature are an example of Secondary Literature.

• Review article:​  Author analyzes and summarizes all of the existing original research by others on a broad topic.  The title may include the phrase “literature review” or sometimes just “review.”    Articles will be scholarly and appear in academic journals.
• News: ​Author summarizes recent research for a general or lay audience.