- Religion : Belief in, and systems of, worshipful dedication to a superhuman power or belief in the ultimate nature of existence.
- Allah : Add brief definition or description
- Al-Azhar University : Located in Cairo,Egypt, while associated with conservative Sunni, generally considered the world's premier educational institution in Islamic studies
- Dar al-Hab : Add brief definition or description
- Dar al-Islam : That part of the world where Islam is dominant and government is in accordance with Sharia law
- Fatwa : A decree, usually ordering or forbidding action, on a point of Sharia; it is assumed to have been issued by a qualified scholar, but there is a more general acceptance that it must be accepted by a community of scholars to be valid; there is dispute if other than the issuer can revoke it
- Hadith : Add brief definition or description
- Ijtihad : In Islam, interpretation of other than infallible Qur'anic revelation; some sects believe that interpretation ended circa the 13th century while others allow interpretation by qualified jurists (alim (singular), ulema}
- Jahiliyya : At the most basic, the state of ignorance of Islam; according to Sayyid Qutb, the failure to accept Allah as the ultimate authority by accepting secular government
- Jihad : Literally meaning "struggle", a Muslim concept that can refer to an inward-directed personal process to submit to God's will, or to an external combat with the enemies of Islam
- Kafir : Add brief definition or description
- Lailaha illalah : Add brief definition or description
- Muhammad : An Arab prophet and the founder of Islam (570-632 CE).
- Qur'an : The sacred book of Islam, consisting of revelations to Muhammad.
- Salafism : A strict branch of Sunni Islam, dedicated to the restoration of the Caliphate, often by means of armed jihad
- Sayyid : A title or name for a Muslim who can trace his ancestry to the family of the Prophet Muhammad; there are multiple variations of language and transliteration
- Sharia : The Muslim system of law and rule of conduct inspired by the Qur'an, the Sunna, traditional law systems, and the Hadiths.
- Shirk : An Arabic word literally meaning polytheism, but interpreted by some Salafist clerics, such as Abu Muhammad al-Maqdisi, to include allegiance to any government, even ostensibly Islamist, which does not follow strict Sharia law.
- Shi'a : A Muslim who believes that the line of religious authority derives from the Household of the Prophet Muhammad (Ahl ul-bayt), through the line of his son-in-law, Imam Ali
- Sufism : Add brief definition or description
- Sunna : Add brief definition or description
- Sunni : The main branch of Islam, which treats authority as following in the line of the first four "righteously guided" caliphs, as opposed to the Shi'ite dynastic line from the son-in-law of the Prophet
- Takfir : A Muslim, primarily Salafist practice of excommunication or shunning of non-observant Muslims; it may extend to killing them
- Tawhid : Basic Islamic belief about the oneness of God; an interpretation, Tawhid al-Hakimiyah, is important in radical Islamism
- Ummah : Add brief definition or description
- Wahhabism : A socially conservative branch of Sunni Islam, strongest in the House of Saud, which rules Saudi Arabia
- Afghanistan : A Islamic republic in Central Asia, with an unstable but elected government; borders China, Iran, Pakistan, Uzbekistan, Tajikistan, Turkmenistan
- Indonesia : A country in Southeast Asia.
- Iran : Country in the Middle East.
- Iraq : Country in the Middle East, currently transitioning from rule by the US.
- Saudi Arabia : A country in the Middle East, governed by a monarchy under Islamic law, which includes the most revered sites in Islam, and also dominates the world's oil economy.