Sunni, Shi`a, Kharijite, Sufi, Schools of Fiqh, Hanafi, Deobandi, Barelwi, Hanbali, Maliki, Shafi'i, Ash'ari, Maturidi, Murjite, Mu'tazili, Twelvers, Usooli, Akhbari, Shaykhi, Alevi, Ismailiyah, Nizari, Alawi, Druze, Bohras, Dawoodi Bohras, Sulamaini Bohras, Alavi Bohras, Zaiddiyah, badi, Sufri, Sufi Orders, Bektashi, Chishti, Naqshbandi, Oveyssi, Qadiri, Suhrawardiyya, Salafism,
Wahhabism, Tablighi Jama'at, Zikri, Ahmadiyya,
Nation of Islam, Moorish Science,, Qur'an Alone, Yazidi,
B�bism, Bah�'� Faith, Five Percenters and Nuwaubu.
The above are faiths within Islam. The reason why you have probably never heard of most of them is because they are completely harmless and not terrorists. The bad apple in the bunch are the Wahhabis.
Wahhabism
Wahhabism was revived by the 18th-century teacher Muhammad ibn Abd al Wahhab in the Arabian peninsula, and was instrumental in the rise of the House of Saud to power. Wahhabism is a puritanical and legalistic Islamic movement under the Sunni umbrella, and is the dominant form of Islam in Saudi Arabia. In addition to the Qur'an and hadith, it also accepts various commentaries including Ibn Abd al-Wahhab's Kitab al-Tawhid ("Book of Monotheism"), and the works of the earlier scholar Ibn Taymiyya.
In short, they are extreme and have lots of money (remember when you next fill up with petrol and make an unnecessary journey). They are not representative of the Muslim faith as a whole, in fact, it is they that give the rest a bad name.