A fatwā (Arabic: فتوى; plural fatāwā Arabic: فتاوى) in the Islamic faith is a nonbinding but authoritative legal opinion or learned interpretation that the Sheikhul Islam, a qualified jurist or mufti, can give on issues pertaining to the Islamic law. The person who issues a fatwā is called, in that respect, a mufti, i.e. an issuer of fatwā, from the verb أَفْتَى 'aftā = "he gave a formal legal opinion on". This is not necessarily a formal position since most Muslims argue that anyone trained in Islamic law may give an opinion (fatwā) on its teachings. If a fatwā does not break new ground, then it is simply called a ruling.
An analogy might be made to the issue of legal opinions from courts in common-law systems. Fatwās generally contain the details of the scholar's reasoning, typically in response to a particular case, and are considered binding precedent by those Muslims who have bound themselves to that scholar, including future muftis; mere rulings can be compared to memorandum opinions. The primary difference between common-law opinions and fatwās, however, is that fatwās are not universally binding; as Sharia is not universally consistent and Islam is very non-hierarchical in structure, fatwās do not carry the sort of weight as that of secular common-law opinion.
In a religious context, the word fatwa carries more meaning. This is because when a Muslim has a question that they need to be answered from an Islamic point of view, they ask an Islamic scholar this question, and the answer is known as a fatwa. This fatwa is said by followers to carry more weight than just the random opinion of any person. Muslim scholars are expected to give their fatwa based on religious scripture, not just their personal opinions. Therefore, their fatwa is sometimes regarded as a religious ruling. Here is an example of a fatwa: Muslims are expected to pray five times every day at specific times during the day. A person who is going to be on a 12-hour flight may not be able to perform their prayers on time. So they might ask a Muslim scholar for a fatwa on what is the appropriate thing to do, or they might look up the answer in a book or on the internet. The scholar might advise them to perform the prayer to the best of their ability on the plane, or to delay their prayer until they land, for example. And they would support their opinion with scripture. The fatwa is not legally binding or final, it is a respected interpretation of the sharia given by a mufti on a particular case. If the individual doesn't like the fatwa given, he/she can seek out another Mufti or Qadi for a second opinion which might have the desired outcome.