Islam is based on two major sources: the Qur'an and the Sunnah, and the latter is available to us in the form of hadiths. The Prophet (S) said,"Whoever comes to know one hadith of mine should spread it." This book contains 200 small but important hadiths which can be easily memorized and spread to others.
Muslims believe that Sahih Muslim is the most authentic book of Hadith after Sahih Al-Bukhari. Hadith are the sayings, actions, and approvals of the Prophet (S) which have been preserved by great scholars like Imam Muslim.