In Islam, the Arabic word sunnah has come to denote the way Prophet Muhammad (saas), the Messenger of Allah, lived his life. The Sunnah is the second source of Islamic jurisprudence, the first being the Qur'an. Both sources are indispensable; one cannot practice Islam without consulting both of them. The Arabic word hadith (pl. ahadith) is very similar to Sunnah, but not identical. A hadith is a narration about the life of the Prophet (saas) or what he approved - as opposed to his life itself, which is the Sunnah as already mentioned.
In M. M. Azami's Studies in Hadith Methodology and Literature, the following precise definition of a hadith is given,
"According to Muhaddithiin [scholars of hadith -ed.] it stands for 'what was transmitted on the authority of the Prophet, his deeds, sayings, tacit approval, or description of his sifaat (features) meaning his physical appearance. However, physical appearance of the Prophet is not included in the definition used by the jurists.'
Thus hadith literature means the literature which consists of the narrations of the life of the Prophet and the things approved by him. However, the term was used sometimes in much broader sense to cover the narrations about the Companions [of the Prophet -ed.] and Successors [to the Companions -ed.] as well. "
Professor Muhammad Mustafa Al-Azami,
one of the world's premier scholars of Hadith, was born in Mau, India in the early 1930s and received his education successively at Dar al-Ulum Deoband, India (1952), al-Azhar University, Cairo (M.A., 1955), and University of Cambridge (Ph.D., 1966). He is Professor Emeritus at King Sa'ud University (Riyadh) where he also chaired the department of Islamic Studies; he holds a Saudi citizenship. Al-Azami served as curator of the National Public Library, Qatar; Associate Professor at Umm al-Qura University (Makkah); Visiting Scholar at University of Michigan (Ann Arbor); Visiting Fellow at St. Cross College (University of Oxford); King Faisal Visiting Professor for Islamic Studies at Princeton; and Visiting Scholar at University of Colorado (Boulder). He is also an Honorary Professor at University of Wales (Lampeter). His publications include Studies in Early Hadith Literature, Hadith Methodology and Literature, On Schacht's Origins of Muahmmadan Jurisprudence, Dirasat fi al-Hadith an-Nabawi, Kuttab an-Nabi, Manhaj an-Naqd 'ind al-Muhaddithin, and al-Muhaddithun min al-Yamamah. Among his credited works are al-Ilal of Ibn al-Madini, Kitab at-Tamyiz of Imam Muslim, Maghazi Rasulullah of Urwah ibn Zubayr, Muwatta Imam Malik, Sahih ibn Khuzaimah, and Sunan ibn Majah. Many of al-Azami's works have been translated internationally, and his forthcoming works include The Qur'anic Challenge: A Promise Fulfilled, and The Isnad System: Its Origins and Authenticity. In 1980 he was the recipient of the prestigious King Faisal International Award for Islamic Studies.