Sunna refers to the practices, teachings, and examples set by the Prophet Muhammad in Islam. It serves as a guide for Muslims on how to live their lives according to the principles of their faith. The Sunna complements the Qur'an, which is the holy book of Islam, providing context and practical applications of its teachings. The Sunna is recorded in collections known as Hadith, which are accounts of the Prophet's sayings and actions. These texts are essential for understanding Islamic law and ethics, as they help clarify the principles outlined in the Qur'an and offer insights into the daily life of a practicing Muslim.