The term periodicals includes:

- Newspapers

- Magazines

- Journals

There are three major categories of periodicals

- Popular Publications

- Scholar Journals

- Trade Publications

Each type is targeted towards a different audience.

Popular publication includes both magazines and newspapers.

These publications:

- are published by profit making companies.

- are targeted to the general public, consequently they strive for a broad appeal.

- contain a large amount of advertising targeted at the readers of the magazine or newspaper.

- incorporate a lot of visual appeal (images, bright colors, etc.) in order to catch the eye of a potential reader. For example, magazines in the checkout line of supermarkets.

- are often focused on one topic area with broad appeal (news, sports, cooking, health, etc.).

- Articles in popular publications cover a wide range of topics.

- Articles are written at a level that the average person can enjoy.

- Articles are written by staff members or free lance writers.

- Editors working for the publication select the articles that will be included in each issue.

- Article length can vary greatly from a single paragraph to upwards of 10 pages (sometimes more) for an in-depth news article or essay.

Scholarly journals are also known as peer-reviewed journals

These publications:

- are targeted towards scholars,researchers, and academics.

- focus on a very specific topic area. For example, atmospheric physics, cancer medicine, or medieval literature.

- are sometimes published by non-profit institutions like a college or university.

- have a serious/stark look using few photographs, colors, or images. In some ways they often look very much like a book.

- contain little (if any) advertising, often for other publications by the publisher of the journal.

- frequently use footnotes and bibliographies.

- Many articles describe the author's original research.

- Some articles discuss current research by others in a particular field.

- Articles are written at a scholarly level, using the language and jargon of the particular field of study.

- Articles for publication are selected by a board of scholars or peers (hence the use of the peer-reviewed term) in the same field of study, .

- Articles are long with 10, 20, 30 page (and longer) articles being common. Rarely is an article less that about 6 or 7 pages long.

Trade Publications are also called trade journals

These publications:

- are targeted towards and use the language of a specific business, industry, or profession.

- could be published by either a profit making company or a non-profit professional organization (for example the National Association of Broadcasters).

- contain plenty of advertising for the goods and services used by a given business, industry, or profession.

- use a lot of imagery and colors (much like popular publications).

Articles in Trade Publications:

- focus on the news, trends, and products associated with a given business, industry, or profession.

- are selected for publication by editors working for the trade journal.

- tend to be somewhat shorter with articles running more than 8-10 pages being uncommon.