苏拉（سورة‎ sūrah，复数 suar سور‎）一词是阿拉伯语，是“被篱笆或墙所围起来”的意思。这个词也可表示“图片”或“彩绘”的意思。苏拉在古兰经里是“章”的意思，古兰经的内文就是按照每章的长度编排的，大体而言长的在前，短的在后，并不是依照启示时间排序的。每个苏拉根据该苏拉经文的关键字来命名，但也有依主题来命名的，例如第一章“开端”章。有些苏拉在穆罕默德时代启示的时候令当时的穆斯林大为震惊。例如，犹太妇女、耶稣基督的母亲马利亚（古兰经称为「***」）在第19个苏拉就被提及。

古兰经共有114个苏拉，分为“麦加篇章”与“麦地那篇章”，分别是穆罕默德在麦加以及麦地那所受的启示。但是有少数麦加篇章混有麦地那时期的经文，也有少数麦地那篇章混有麦加时期的经文。学者推断，某些苏拉其实是后来和别的苏拉合成的，原本并不单独成篇。另外，除了第九章苏拉，每章苏拉都以“太斯米”起头，就是所谓的“奉至仁至慈真主之名”。

A Surah (/ˈsʊərə/; also spelled Surat, Sura; Arabic:سورة‎ sūrah, plural سور suwar) is a chapter of the Qur'an. There are 114 surahs in the Qur'an, each divided into verses. The chapters or suras are of unequal length, the shortest chapter (Al-Kawthar) has only three ayat (verses) while the longest (Al-Baqara) contains 286 verses. Of the 114 chapters in the Qur'an, 86 are classified as Meccan, while 28 are Medinan. This classification is only approximate in regard to location of revelation; any chapter revealed after migration of Muhammad to Medina (Hijrah) is termed Medinan and any revealed before that event is termed as Meccan. The Meccan chapters generally deal with faith and scenes of the Hereafter while the Medinan chapters are more concerned with organizing the social life of the nascent Muslim community and leading Muslims to the goal of Dar al-Islam by showing strength. Except sura At-Tawba, all chapters or suras commence with 'In the Name of God, the Merciful, the Compassionate'. This formula is known as the Bismillah and denotes the boundaries between chapters. The chapters are arranged roughly in order of descending size therefore the arrangement of the Qur'an is neither chronological nor thematic. Suras (chapters) are recited during the standing portions (Qiyam) of Muslim prayers. Sura Al-Fatiha, the first chapter of the Qur'an, is recited in every unit of prayer and some units of prayer also involve recitation of all or part of any other sura.