A Dictionary of Islam Being a cyclopedia of the...

3. Āyah (pl. Āyāt), Verses. Āyah (Heb. אוֹת) is a word which signifies “sign.” It was used by Muḥammad for short sections or verses of his supposed revelation. The division of verses differs in different editions of the Arabic Qurʾān. The number of verses in the Arabic Qurʾāns are recorded after the title of the Sūrah, and the verses distinguished in the text by a small cypher or circle. The early readers of the Qurʾān did not agree as to the original position of these circles, and so it happens that there are five different systems of numbering the verses.

4. Sūrah (pl. Suwar), Chapters. A word which signifies a row or series, but which is now used exclusively for the chapters of the Qurʾān, which are one hundred and fourteen in number. These chapters are called after some word which occurs in the text, and, if the Traditions are to be trusted, they were so named by Muḥammad himself, although the verses of their respective Sūrahs were undoubtedly arranged after his death, and sometimes with little regard to their sequence. Muslim doctors admit that the K͟halīfah ʿUs̤mān arranged the chapters in the order in which they now stand in the Qurʾān.

The Sūrahs of the Muḥammadan Qurʾān are similar to the forty-three divisions of the Law amongst the Jews known as סְדָרִים Sidārīm, or “orders.” These were likewise named after a word in the section, e.g. The first is Bereshith, the second Noah, &c. (See Buxtorf’s Tiberias, p. 181.)