What is Fiqh?
Fiqh is the name given to jurisprudence in Islam… In its widest sense, it covers all aspects of religious, political and civil life. In addition to the laws regulating ritual and religious observances (‘ibaadaat), as far as concerns performance and abstinence, it includes the whole field of family law, the law of inheritance, of property and of contract, in a word, provisions for all the legal questions that arise in social life (mu‘aamalaat); it also includes criminal law and procedure and finally constitutional law and laws regulating the administration of the state and the conduct of war. All aspects of public and private life and business should be regulated by laws recognized by religion; the science of these laws is fiqh. (Shorter Encyclopaedia of
Islam, p. 102)
Taken from A commentary on Usool ul Fiqh made easy by Dr. Abu Ameenah Bilal Philips