Liguistically Sunnah refers to the path or way. In fact the root of the word is [sanna] which means literally smooth and easy flow. In Islam Sunnah refers to the way of life prescribed as normative for Muslims on the basis of the teachings and practices of Muhammad and interpretations of the Quran. It has been institutionalized as one of the sources of sharī‘ah, the other source being the Quran. In other words Sunnah denotes the practices of Prophet Muhammad that he taught and practically instituted as a teacher of the sharī‘ah and the best exemplar.
What does Sunnah include?
According to Muslims, Sunnah includes everything the Prophet Muhammad, the Messenger of Allah, did in his way of life. This includes his specific words, habits, practices,and silent approvals. The significance of this relies on the importance Sunnah tells us about how the Prophet of Allah addresses the different incidents that occurred in his life. How he dealt with friends, family and government. These are considered as teachings that Muslims must adhere to. The term "Sunni" denotes those who claim to practice these usages, as part of the Umma
