What is the difference between trade, professional and peer reviewed journals?

Short articles, which report news and current events.

Articles have no shared structure. They are frequently of different lengths, style and content within one issue.

Articles do not use a systematic form to refer to other peoples publications or words (quotations).

Frequently published, usually weekly.

Articles do not have bibliographies.

Authors are not identified.

Authors are professional journalists.

The decision to publish is the editors alone.

Long articles that report the results of research.

Articles have a set structure usually containing: i) an abstract; ii) literature review; iii) justification of research; iv) methodology; v) results; vi) conclusions and suggestions for further research.

Journals have a system of referencing or referring to other publications mentioned in the text. The Harvard System (name - date) is an example.

Published monthly or quarterly.

Have extensive bibliographies.

Authors are identified, usually giving their place of employment such as a university or research institute.

Authors are academics or researchers.

Articles are reviewed by referees to ensure quality. This process is called peer review.  Journals that use this process are called Peer Reviewed Journals or Refereed Journals.