The colon, :, is a punctuation mark consisting of two equally sized dots aligned vertically. A colon often precedes an explanation, a list, or a quoted sentence. It is also used between hours and minutes in time, between certain elements in medical journal citations, between chapter and verse in Bible citations, and, in the US, for salutations in business letters and other formal letter writing.

Chapter and verse divisions did not appear in the original texts of Jewish or Christian bibles; such divisions form part of the paratext of the Bible. Since the early 13th century, most copies and editions of the Bible have presented all but the shortest of the scriptural books with divisions into chapters, generally a page or so in length. Since the mid-16th century, editors have further subdivided each chapter into verses – each consisting of a few short lines or of one or more sentences. In the King James Version (KJV) Esther 8:9 is the longest verse and John 11:35 is the shortest. Sometimes a sentence spans more than one verse, as in the case of Ephesians 2:8–9, and sometimes there is more than one sentence in a single verse, as in the case of Genesis 1:2.