Fiqh (; ) is Islamic jurisprudence. "Fiqh" is often described as the human understanding and practices of the "sharia," that is human understanding of the divine Islamic law as revealed in the Quran and the "Sunnah" (the teachings and practices of the Islamic prophet Muhammad and his companions). Fiqh expands and develops Shariah through interpretation ("ijtihad") of the Quran and "Sunnah" by Islamic jurists ("ulama") and is implemented by the rulings ("fatwa") of jurists on questions presented to them. Thus, whereas "sharia" is considered immutable and infallible by Muslims, "fiqh" is considered fallible and changeable. "Fiqh" deals with the observance of rituals, morals and social legislation in Islam as well as political system. In the modern era, there are four prominent schools ("madh'hab") of "fiqh" within Sunni practice, plus two (or three) within Shi'a practice. A person trained in "fiqh" is known as a "faqīh" (plural "fuqaha").