Muslims believe that the Quran was verbally revealed by God to the final Prophet Muhammad through the archangel Gabriel (Jibril), gradually over a period of approximately 23 years, beginning on 22 December 609 CE, when Muhammad was 40, and concluding in 632, the year of his death. Muslims regard the Quran as the most important miracle of Muhammad, a proof of his prophethood, and the culmination of a series of divine messages that started with the messages revealed to Adam and ended with Muhammad. The word "Quran" occurs some 70 times in the text of the Quran, although different names and words are also said to be references to the Quran.
According to the traditional narrative, several companions of Muhammad served as scribes and were responsible for writing down the revelations. Shortly after Muhammad's death, the Quran was compiled by his companions who wrote down and memorized parts of it. These codices had differences that motivated the Caliph Uthman to establish a standard version now known as Uthman's codex, which is generally considered the archetype of the Quran known today. There are, however, variant readings, with mostly minor differences in meaning.
The Quran assumes familiarity with major narratives recounted in the Biblical scriptures. It summarizes some, dwells at length on others and, in some cases, presents alternative accounts and interpretations of events. The Quran describes itself as a book of guidance for mankind 2:185. It sometimes offers detailed accounts of specific historical events, and it often emphasizes the moral significance of an event over its narrative sequence.Hadith are additional oral and written traditions supplementing the Quran; from careful authentication they are believed to describe words and actions of Muhammad, and in some traditions also those closest to him. In most denominations of Islam, the Quran is used together with hadith to interpret sharia (Islamic) law; in a small number of denominations, only the Quran is used as a source. During prayers, the Quran is recited only in Arabic.
Someone who has memorized the entire Quran is called a hafiz. Quranic verse (ayah) is sometimes recited with a special kind of elocution reserved for this purpose, called tajwid. During the month of Ramadan, Muslims typically complete the recitation of the whole Quran during tarawih prayers. In order to extrapolate the meaning of a particular Quranic verse, most Muslims rely on exegesis, or tafsir.
The word qurʼān appears about 70 times in the Quran itself, assuming various meanings. It is a verbal noun (maṣdar) of the Arabic verb qaraʼa (قرأ), meaning "he read" or "he recited". The Syriac equivalent is (ܩܪܝܢܐ) qeryānā, which refers to "scripture reading" or "lesson". While some Western scholars consider the word to be derived from the Syriac, the majority of Muslim authorities hold the origin of the word is qaraʼa itself. Regardless, it had become an Arabic term by Muhammad's lifetime. An important meaning of the word is the "act of reciting", as reflected in an early Quranic passage: "It is for Us to collect it and to recite it (qurʼānahu)."
In other verses, the word refers to "an individual passage recited [by Muhammad]". Its liturgical context is seen in a number of passages, for example: "So when al-qurʼān is recited, listen to it and keep silent." The word may also assume the meaning of a codified scripture when mentioned with other scriptures such as the Torah and Gospel.
The term also has closely related synonyms that are employed throughout the Quran. Each synonym possesses its own distinct meaning, but its use may converge with that of qurʼān in certain contexts. Such terms include kitāb (book); āyah (sign); and sūrah (scripture). The latter two terms also denote units of revelation. In the large majority of contexts, usually with a definite article (al-), the word is referred to as the "revelation" (waḥy), that which has been "sent down" (tanzīl) at intervals. Other related words are: dhikr (remembrance), used to refer to the Quran in the sense of a reminder and warning, and ḥikmah (wisdom), sometimes referring to the revelation or part of it.
The Quran describes itself as "the discernment" (al-furqān), "the mother book" (umm al-kitāb), "the guide" (huda), "the wisdom" (hikmah), "the remembrance" (dhikr) and "the revelation" (tanzīl; something sent down, signifying the descent of an object from a higher place to lower place). Another term is al-kitāb (The Book), though it is also used in the Arabic language for other scriptures, such as the Torah and the Gospels. The term mus'haf ('written work') is often used to refer to particular Quranic manuscripts but is also used in the Quran to identify earlier revealed books.