Mecca, Arabic Makkah, ancient Bakkah, city, western Saudi Arabia, located in the Ṣirāt Mountains, inland from the Red Sea coast. It is the holiest of Muslim cities. Muhammad, the founder of Islam, was born in Mecca, and it is toward this religious centre that Muslims turn five times daily in prayer. All devout and able Muslims attempt a hajj (pilgrimage) to Mecca at least once in their lifetime. Because it is sacred, only Muslims are allowed to enter the city.

mosque, Arabic masjid or jāmiʿ, any house or open area of prayer in Islam. The Arabic word masjid means “a place of prostration” to God, and the same word is used in Persian, Urdu, and Turkish. Two main types of mosques can be distinguished: the masjid jāmiʿ, or “collective mosque,” a large state-controlled mosque that is the centre of community worship and the site of Friday prayer services; and smaller mosques operated privately by various groups within society.

Muhammad, in full Abū al-Qāsim Muḥammad ibn ʿAbd Allāh ibn ʿAbd al-Muṭṭalib ibn Hāshim, (born c. 570, Mecca, Arabia [now in Saudi Arabia]—died June 8, 632, Medina), the founder of Islam and the proclaimer of the Qurʾān. Muhammad is traditionally said to have been born in 570 in Mecca and to have died in 632 in Medina, where he had been forced to emigrate to with his adherents in 622.

The Qur'an is the primary religious text of Islam, which according to Islamic tradition was revealed to Muhammad. There are several important differences between the Qur'an, the Tanakh (Old Testament), and the New Testament. The Tanakh and the New Testament both consist of multiple books that were composed independently and assembled at a later date, representing a variety of literary genres. The Qur'an is a single work, divided into 114 chapters called sura, consisting of a series of revelations given over a period of years. Originating as an oral work, it was written down during Muhammad's life and compiled into a single work shortly after his death. Further, while many Jews and Christians consider the Tanakh and the New Testament to be divinely inspired, the Qur'an is considered the literal words of God, transmitted to Muhammad by the angel Gabriel.

hajj, also spelled ḥadjdj or hadj, in Islam, the pilgrimage to the holy city of Mecca in Saudi Arabia, which every adult Muslim must make at least once in his or her lifetime. The hajj is the fifth of the fundamental Muslim practices and institutions known as the Five Pillars of Islam. The pilgrimage rite begins on the 7th day of Dhū al-Ḥijjah (the last month of the Islamic year) and ends on the 12th day.

The official Islamic calendar is lunar, with year one coinciding with the year 622 C.E., the date of Muhammad's migration (hijra) from Mecca to Medina. This calendar was adopted during the reign of the second caliph ˓Umar. The Hijri lunar calendar is used as the basis for computing the official months (ahilla, new moons), and for determining the dates for important religious activities such as fasting and pilgrimage.

Ramadan, Arabic Ramaḍān, in Islam, the ninth month of the Muslim calendar and the holy month of fasting. It begins and ends with the appearance of the crescent moon. Because the Muslim calendar year is shorter than the Gregorian calendar year, Ramadan begins 10–12 days earlier each year, allowing it to fall in every season throughout a 33-year cycle.

Mawlid al-Nabi, or simply Mawlid (with many variant spellings) is a celebration of the birth of the prophet Muhammad, founder of Islam, in about 570 CE. Mawlid is derived from an Arabic word meaning to give birth, and in some countries, including Egypt and Sudan, is used as a general term for the birthday of a Sufi saint. There is disagreement about the precise origins of the celebration of Mawlid al-Nabi, as it was not observed or commanded by Muhammad.

Laylat al-Qadr, (Arabic: “Night of Power”) Islamic festival that commemorates the night on which God first revealed the Qurʾān to the Prophet Muhammad through the angel Gabriel.

(Arabic: “Festival of Breaking Fast”) also spelled ʿĪd al-Fiṭr, also called al-ʿĪd al-Ṣaghīr, Turkish Ramazan Bayrami (“Ramadan Festival”) , first of two canonical festivals of Islam. Eid al-Fitr marks the end of Ramadan, the Muslim holy month of fasting,

Sufism, mystical Islamic belief and practice in which Muslims seek to find the truth of divine love and knowledge through direct personal experience of God. It consists of a variety of mystical paths that are designed to ascertain the nature of humanity and of God and to facilitate the experience of the presence of divine love and wisdom in the world.

Sunni, Arabic Sunnī, member of one of the two major branches of Islam, the branch that consists of the majority of that religion’s adherents. Sunni Muslims regard their denomination as the mainstream and traditionalist branch of Islam—as distinguished from the minority denomination, the Shiʿah.

Also called Shiʿi, Arabic Shīʿī, Shiʿite, collective Shiʿah or Arabic Shīʿah, member of the smaller of the two major branches of Islam, the Shiʿah, distinguished from the majority Sunnis.