The punctuation mark used to indicate a pause in a sentence is the comma.
A comma is a short punctuation mark that commonly separates items in a list, clauses in a sentence, introductory phrases, and words of direct address. It can make the structure of a sentence easier to follow, although it does not always represent a pause when read aloud.
Commas are often confused with stronger punctuation marks. A colon usually introduces an explanation, example, or list; a semicolon links closely related independent clauses; and a period normally ends a declarative sentence. A comma alone cannot properly join two complete sentences, a mistake known as a comma splice.
Usage varies somewhat between style guides, particularly over the so-called Oxford comma before the final item in a list. For example, “red, blue, and green” includes it, while “red, blue and green” does not. Both conventions are used, but consistency matters. In every case, the comma’s role is grammatical as well as rhythmic.