A citation or source citation is a reference to a published work (for example, a book, article, image, etc.,) that is used when creating a written work. It shows readers where specific pieces of information came from and where readers can locate it for themselves. It acknowledges or gives credit to the author who actually created the content being used in a paper. The opposite of a citation is plagiarism, or not giving credit to others for their ideas, concepts, or images. Plagiarism, especially in Academia, is considered taking the work of others and presenting it as one's own. The penalties for plagiarism can be severe. Source citations also give a work credibility. In other words, it shows the information is simply not made up.

What to cite 
In general, different academic situations will have different rules for what to cite and how to cite it. Some use footnotes while others may require in-text (also called inline) source citations.(←This is an inline source citation) Some may require a bibliography which lists all works that were used. In some cases, it may only be necessary to provide a list of "works cited." It is important to know in advance what protocols must be used and what citation style (see below) is preferred.

 Quotations Anything taken word-for-word from a source must be shown in quotation marks (" "). The quotation must have a source citation showing where the quoted text came from.

For example: "Quality or junk? How do you want your research described by others?"

 Paraphrase To paraphrase is to take someone's words or ideas and put them in the words of the person writing the paper. Anything paraphrased should be source cited. A paraphrase is usually about the same number of words as the original but does not use quotation marks.

Example (original text): "And there is only one fault so obvious, so fundamental, that it instantly brands a piece of work as the product of an amateur or careless researcher: poor source citations". Paraphrased: Poor quality source citations usually indicate that a piece of work is either careless research or the work of an amateur.

 Summarize A summary is a short version of another work in the writer's own words. A summary is usually shorter than the original. When summarizing someone else's work, a source citation is necessary.

Example (original text): "When you don’t know when to cite, you end up plagiarizing which is just a big word for stealing and that’s mean. And when you plagiarize, you also get an “F” and people think, “Dude, that kid is one dumb bunny.” Let’s avoid that, shall we?" Summarized: When you do not understand source citations, it is easy to plagiarize someone else's work. So you do not get an "F" for your work, the following are the basic rules.

 Facts and ideas Using facts and information to support an argument generally requires a source citation. Facts do not always need to be source cited, especially if they are commonly known (e.g. water freezes at 32 degrees Fahrenheit). Ideas, however, should always be cited.

What is not necessary to cite 
You do not need to cite anything that is common knowledge. These are things that would be known by nearly everyone. Examples of common knowledge are:
 Facts that are widely available in many sources. For example: Andrew Jackson was the seventh President of the United States.
 Things that are easy to observe or see. For example: Many people use cell phones today.
 Common sayings. For example: To make a long story short...

But when in doubt, cite it.

What a source citation includes 
A source citation typically includes several key pieces of information including:
 The name of the author or authors.
 The name of the book, article, or publication.
 The date the work was published.
 When it was accessed, if it was found online.
 The URL, if it is an online webpage.
 The place of publication.
 The name of the publisher.
 The page number or numbers. For example, p. 1, 21, 33 (means the information is on these pages) or pp. 55–60 (meaning the information is found on pages 55 through 60).

Citation styles 
The main citation styles that are used include:

 APA style (American Psychological Association) is the style is the most commonly used style in the social sciences. The guideline is found in the Publication Manual of the American Psychological Association, Sixth Edition.

Example (bibliographic style): (Smith, 2004, p. 39) Here "Smith" is the author of a work fully listed in the bibliography. The page number is 39.

 MLA Style (Modern Language Association) is the style used for writing and formatting research papers in the liberal arts and the humanities. One of the references for this style is the MLA Handbook for Writers of Research Papers, Eighth Edition.

Example (author-date style): Smith, William. The Last of the Inupiat Eskimos. Alaska Northwest Books, 1997. p 39. Note the use of periods separating parts of the citation)

 Chicago Manual of Style is the style often used in printed and electronic journals, magazines, and newspapers. It offers two types of citation systems: (1) notes and bibliography and (2) author-date. The notes and bibliography style is used most often in literature, history and the arts. The author-date system is traditionally used in Physics, natural science, and social sciences.

Example (author-date style): William Smith, The Last of the Inupiat Eskimos (Portland, OR: Alaska Northwest Books, 1997), p. 39 (Chicago style allows author last name, first name or first name last name)

References 
(The following are inline source citations)

Other websites 
 When to Cite Your Sources; YouTube
 Citation Generator
 Citation Machine

Writing