"I leave behind me two things, the Qur'an and my example, the Sunnah
and if you follow these you will never go astray." (Prophet Muhammad
[pbuh] during his last sermon on Ninth Day of Dhul Hijjah 10 A.H in
the Uranah Valley of mount Arafat]
Sunnah/Hadith are traditions, practices and saying of Prophet Muhammad (pbuh). The Prophets sunnah are critical in understanding Islam and the Holy Quran. The full meaning or the translation of the Holy Quran cannot be understood until the sunnah is understood because the life of Prophet Muhammad (pbuh) was in the light of the Quran.
Sunnah/Hadith of the Prophet have been written down on paper in many books and it takes scholars years and an entire lifetime to read and understand the vast amount of information and interpret in the context it is in. Muslims strive to live their lives in according to the traditions and practices of Prophet Muhammad (pbuh).