Usul Al-Kafi is a significant collection of hadiths in Shia Islam, compiled by the scholar Al-Kulayni in the 10th century. It serves as a primary source of Islamic teachings, covering various aspects of faith, ethics, and law. The book is divided into three sections: Usul al-Kafi, which deals with theological principles; Furu al-Kafi, focusing on practical laws; and Rawdat al-Kafi, which includes miscellaneous traditions. The collection is highly regarded for its comprehensive nature and authenticity, making it a vital reference for Shia scholars and followers. Usul Al-Kafi aims to preserve the teachings of the Prophet Muhammad and the Imams, ensuring that the core beliefs and practices of Shia Islam are well-documented and accessible.