Sufism or taṣawwuf is defined by its adherents as the inner, mystical dimension of Islam.

A practitioner of this tradition is generally known as a ṣūfī.

They belong to different ṭuruq or "orders"—congregations formed around a master—which meet for spiritual sessions (majalis), in meeting places known as zawiyahs, Khanqahs, or tekke.

Sufi turuq/orders may be either Sunnī, Shī'ī, or mixed in doctrine, and may trace many of their original precepts from the Islamic Prophet Muhammad through his cousin and son-in-law 'Alī, with the notable exception of the Naqshbandi, who trace their origins through the first Caliph, Abu Bakr.

Prominent orders include Ba 'Alawiyya, Chishti, Khalwati, Naqshbandi, Nimatullahi, Oveyssi, Qadiria Boutshishia, Qadiriyyah, Qalandariyya, Sarwari Qadiri, Shadhliyya and Suhrawardiyya.

Sufis believe they are practicing ihsan (perfection of worship) as revealed by Gabriel to Muhammad: "Worship and serve Allah as you are seeing Him and while you see Him not yet truly He sees you."

Sufis consider themselves as the original true proponents of this pure original form of Islam.

They are strong adherents to the principle of tolerance, peace and against any form of violence.

The Sufi have suffered severe persecution by their coreligionist brothers the Wahhabi and the Salafist.Classical Sufis are characterized by their attachment to dhikr, (a practice of repeating the names of God, often performed after prayers) and asceticism.

Sufism gains adherents among a number of Muslims as a reaction against the worldliness of the early Umayyad Caliphate (661-750 CE).

Sufis have spanned several continents and cultures over a millennium, originally expressing their beliefs in Arabic, before spreading into Persian, Turkish and a dozen other languages.