The Quran is divided into thirty Juz' (Ajzâ' in the plural), for its recitation in one month.
Juz' 'Amma is the thirtieth part of the Quran and the most common. It begins at the 78th Surah (An-Naba') and ends at the 114th (An-Nâs); it therefore brings together the shortest Surahs of the Koran.