Ulum al Qur'an
CHAPTER 4: Form, Language and Style
DIVISIONS OF THE TEXT
Aya and SuraAya (pl. ayat) actually means 'sign'. In technical language it is the shortest division of the Qur'anic text, i.e. a phrase or sentence. The revelation is guidance from God to mankind and it is therefore not at all surprising to find that its smallest divisions are called (guiding) 'signs'. The term 'verse' is not appropriate since the Qur'an is not poetry.
Sura (pl. Suwar) means literally 'row' or 'fence'. In technical language, it is the passage-wise division of the Qur'anic text,i.e. a chapter or part, set apart from the preceding and following text.
The Qur'an has 114 suras of unequal length, the shortest consisting of four and the longest of 286 ayat.
All suras (with the exception of Sura 9) begin with the words bismillahir rahmanir rahim. This is not a later addition to the text, but was already used, even before Muhammad's call to prophethood. '
[See Sura 27: 30.]All 114 suras in the Qur'an have names, which serve as a sort of heading. The names are often derived from an important or distinguishing word in the text itself, such as e.g. al-anfal (8) or al-baqara (2). In other cases it is one of the first few words with which the sSra begins e.g. ta-ha (20) or al-furqan (25).