Sufism or taṣawwuf (Arabic: تصوّف) is defined by its adherents as the inner, mystical dimension of Islam. A practitioner of this tradition is generally known as a ṣūfī (صُوفِيّ). 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 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, Shadhiliyya and Suhrawardiyya.
A Dervish or Darvesh (from Persian درویش, Darvīsh via Turkish, Somali: Daraawiish, Arabic: درويش, Darwīš) is someone treading a Sufi Muslim ascetic path or "Tariqah", known for their extreme poverty and austerity. In this respect, Dervishes are most similar to mendicant friars in Christianity or Hindu/Buddhist/Jain sadhus.