All MLA citations feature two essential components, the in-text citation and works cited entry, and rely upon the same central organizing principle, which is to cite the core elements of a source.
In MLA Style, all citations consist of two components. Both are necessary.
1. THE IN-TEXT CITATION
In-text citations tell a reader the minimum amount of information about any given source which is needed to identify the author and location. In-text citations are most often inserted parenthetically between round brackets, e.g. ( ).
2. THE WORKS CITED ENTRY
In MLA, the list of references at the end of the document is referred to as the Works Cited page (or Work Cited, when there is only one source). Each in-text citation corresponds with a Works Cited entry which provides the full referential information for the source should the reader want to find it on their own.
All Works Cited entries must be formatted according to MLA's template of core elements.
While all sources will feature the necessary minimum of citable information, not all sources will feature all nine of the possible core elements. (E.g., journal articles will likely have a version number, while most books will not.) There are exceptional cases--ancient manuscripts without a title or author, for example--but these are very rare.
AUTHOR
The author is the creator of the source. There can be multiple authors in the case of co-created sources. Some sources have no author.
TITLE OF SOURCE
If the source has no container--i.e., if it stands alone, as a book or film would--then the title should be italicized. If the source is published inside of a container--for example, a poem in a book of poetry, or an essay in an anthology--then the title goes in quotation marks, "like this," and the container title is italicized.
TITLE OF CONTAINER
Some sources are independent, such as scholarly monographs or novels, while other sources have a container. The container is the larger element in which the source is housed. Common examples are research articles published in peer-reviewed journals. The article is the source, and the journal is the container. Container titles are always italicized.
CONTRIBUTOR
This is where contributors other than the author(s) are credited. Common examples of contributors include translators and editors. For example, a short story which appears in an edited anthology will have both an author of the story as well as an editor of the anthology. The role of the contributor should be indicated: e.g., John Doe, ed. or John Doe, trans.
VERSION NUMBER
Containers such as peer-reviewed journals are typically released in numbered volumes, usually corresponding with one cycle of the journal's publication (often yearly). In MLA 9th edition, this is indicated in Works Cited entries with the prefix vol. followed by the volume number, e.g., vol. 4. Books are often released in editions (first, second, third, etc.) in which case this feature of the citation corresponds with the version number.
ISSUE NUMBER
Not only do most journals have volume numbers, but they frequently also have issue numbers. A journal which is on its 12th version but which releases four instalments in its publication cycle, for example, will have volume 122, issues 1-4. In MLA 9th edition, this is indicated in Works Cited entries with the prefix no. followed by the issue number, e.g., no. 1.
PUBLISHER
The publisher of the source, irrespective of its media. This could be an academic or literary press, a digital platform, etc.
PUBLICATION DATE
The date the work was published (most importantly, the year).
LOCATION
The exact location where the cited material can be found in the source, for example, a page number in a book or poetry or a website URL. This will vary depending on the medium of the source (print, digital, film, etc.).