It is not possible in this day and age to comprehend the great sacrifices that were made by the hadith masters [muúaddithīn] or the difficulties and barriers they struggled to overcome for the preservation of hadith. It is a result of these sacrifices that today each word, in fact each letter of the aúódõth are fully preserved. The rules the hadith masters established to preserve the hadith and by which this branch of knowledge became a distinct science are necessary for one to learn and make headway into both the knowledge of hadith and principles of hadith [uüñl al-úadīth].. This short booklet is written to introduce the reader to the knowledge of hadith. It discusses important issues such as how the hadith were compiled, the preservation of hadith, principles regarding the authenticity and weakness in a hadith, the importance of hadith and the various types of hadith books. It ends with short biographies of some of the famous hadith masters. This booklet may be looked upon as a first step in acquiring the insight that is necessary for advancing in this science. After reading this booklet, if one feels a renewed connection with the hadith, it is hoped that it will be a way of salvation for its author. The readers are requested to pray for the author, his parents and his family and that Allah bless them in this world and the Hereafter.