Words used for sections of the Qurʾān. (although note there is another word ṣūra which means “image, form, shape” as a theological and legal term, e.g., for “representational images” being prohibited)
***Sura – translated as “chapter” but not in the sense of a linear “chapter” of a book
The word understood to derive from Christian Syriac for a portion of scriptural recitation.
Word occurs in the Qur’an to refer to portions of the text.
There are 114 chapters in the Qur’an, arranged roughly longest to shortest. Each has a title, sometimes first word, sometimes a prominent theme, sometimes a seemingly random word – mnemonic purposes – Muslims use the names to refer to the chapters, not numbers as often found in reference works.
Division into chapters an original practice in Qurʾān manuscripts although maybe not including the name.
http://www.islamic-awareness.org/Quran/Text/Mss/yem1b.html
http://www.unesco.org/webworld/mdm/visite/sanaa/en/present1.html
***Aya – translated as “verse”; but also used to mean “sign” as in “sign of God” (e.g., natural events) and thus linking the Qur’an to God. Often seen to be parallel to Hebrew (ot) and Syriac words for “sign”.
Different counting for number of verses – between 6204 and 6236 (latter common today) – this accounts for why in some books the same verse will have different numbers
These divisions are found in early manuscripts too both for single verses and then special markers for 5 and especially 10 verse divisions.
***Other divisions of the text of the Qur’an also exist but relate to divisions into units for recitation so that the texts can be recited over a given number of days (rubʿ--quarter; nisf – half; juzʾ -- 1/30th; manzil – 1/7th)
Bibliography: A.T. Welch, “Sura”, Encyclopaedia of Islam, second edition. A. Jeffrey, “Aya”, Encyclopaedia of Islam, second edition