Serial comma

A comma placed before the coordinating conjunction in a list of three or more items, as in “red, white, and blue.” Its use varies by editorial style.

Oxford comma: A comma before the final conjunction in a list of three or more items. This is the best-known name for the serial comma, especially in British and American publishing.
Comma: A punctuation mark used to separate parts of a sentence and indicate structure. The serial comma is one specific use of this punctuation mark.
No serial comma: A list-punctuation convention that omits the comma before the final conjunction. This is the direct alternative to using a serial comma.
Eats, Shoots & Leaves: A 2003 book by Lynne Truss about punctuation in English. Its title illustrates how punctuation can alter the reading of a sequence.
Chicago Manual of Style: An American style guide published by the University of Chicago Press. It generally recommends the serial comma in a series.
Coordinating conjunction: A conjunction that joins words, phrases, or clauses of equal grammatical rank. The serial comma appears immediately before a coordinating conjunction in a series.
House style: An organization's preferred rules for spelling, punctuation, formatting, and usage. Publishers and newsrooms settle serial-comma choices through their house styles.
Comma splice: A grammatical error in which a comma joins independent clauses without a coordinating conjunction. It shows that comma placement has rules beyond separating list items.
Associated Press Stylebook: A style guide used widely in journalism and public relations. It generally omits the serial comma unless needed to prevent confusion.
List punctuation: Punctuation conventions for separating and organizing items in a list. The serial comma is a choice within the broader system of list punctuation.

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English punctuationRelated: Its use can clarify list structure, though English styles differ on whether to require it.