The collector of the hadith Book Sahih Muslim (صحيح مسلم), Muslim Ibn Al-Hajjaj, was born in 204 AH (817/18 AD) in Neshapur (in modern Iran) and died in the city of his birth in 261 AH (874/75 AD). He traveled extensively to compile his collection of hadiths, including Iraq, the Arabian Peninsula, Syria, and Egypt.

Out of the 300,000 hadiths he reviewed, about 12,000 were extracted to be included in his collection based on strict acceptance criteria. Every report in its collection was scrutinized, and the veracity of the journalists' chain was worked out with great diligence. Sahih Muslim is divided into 43 books with a total of 9200 traditions. However, it is important to understand that Muslim Ibn al-Hajjaj never claimed to have collected all the authentic narrations because his purpose was only to collect such narrations on which all Muslims agree.

According to Mundhari, Sahih Muslim has a total of 2200 hadiths (without repetition). According to Muhammad Amin, there are 1,400 authentic hadiths listed in other books, basically a collection of six major hadiths.

The collector of the hadith Book Sahih Bukhari (صحيح البخاري), Muhammad Al-Bukhari (Abū ʿAbd Allāh Muḥammad ibn Ismāʿīl ibn Ibrāhīm al-Juʿfī al-Bukhārī), was born in 194 AH (810/21 AD) in Bukhara (Uzbekistan) and died in the city of his birth in 256 AH (870/01 AD) in Samarkand (Uzbekistan). His dedication to his work led him to travel extensively, including Saudi Arabia, Syria, Kufa, Basra, Egypt, Yemen, and Baghdad, to compile his collection of hadiths.

Sahih al-Bukhari is a comprehensive collection of approximately 7,563 hadiths in 97 chapters. This extensive compilation forms the basis of a complete system of jurisprudence without qasida. The book's thoroughness is highly regarded among Sunni Muslims, and most Sunni scholars consider it second only to the Quran

In the reign of Abbasid Caliph al-Wathiq (AD 842–847), al-Bukhari compiled the book mainly in the Hijaz, in the Grand Mosque in Mecca and the Prophet's Mosque in Medina, two of the most sacred places in Islam. He completed his work in Bukhara, his birthplace, and at an Islamic learning center. His teachers, Ahmad ibn Hanbal, Ali ibn al-Madinah, and Yahya ibn Mu'in, renowned scholars of their time, reviewed the work.

The collector of the hadith Book Sunan Abi Dawud (سنن أبي داود), Abu Dawud Al-Sijistani, was born (889 AD) in Sistan (southwestern Afghanistan, south-eastern Iran, and extending across the borders of southwest Pakistan), he later died in the city of Basrah, Iraq. His dedication to his work led him to travel extensively, including to Egypt, Iraq, and Syria, to compile his collection of hadiths. He studied under Imam Ahmad Ibn Hanbal. Total Number of hadith in Sunan Abi Dawud are 4800.

Abu Dawood's had a unique approach to the hadith collection. He compiled twenty-one books on hadith, selecting only those that he used as
evidence for the companions of Muhammad (May God bless him and grant him peace).The hadiths in Sunan Abi Dawood are meticulously organized into three sections. The first section includes what was mentioned by Imam Bukhari and Imam Muslim, while the second section comprises what met Bukhari or Muslim conditions. It's important to note that Bukhari himself stated: “I only included in my book the authentic hadiths from Sahih Bukhari, and I left out more of these authentic hadiths to avoid being too long.” This division provides a clear structure and aids in understanding the content of the collection.

Abū ʿAbd Allāh Muḥammad ibn Yazīd Ibn Mājah al-Rabʿī al-Qazwīnī, the collector of the hadith Book Sunan Ibn Majah (سُنن ابن ماجه), was born in (824 AD) in Qazvin, Persia and died in the city of his birth in (887 or 889). His dedication to his work led him to travel extensively, visiting key locations such as Iraq, Makkah, the Levant, and Egypt, to compile his collection of hadiths.

His thirst for knowledge led him to study under a diverse array of scholars, including Muḥammad ibn ʻAbdillāh ibn Numayr, Ibn Abi Shaybah (through whom came over a quarter of al-Sunan), Jubārah ibn al-Mughallis, Ibrāhīm ibn al-Mundhir al-Ḥizāmī, Muḥammad ibn Rumḥ, ʻAbdullāh ibn Muʻāwiyah, Hishām ibn ʻAmmār, Dāwūd ibn Rashīd and others. This diverse education greatly enriched his understanding and collection of hadiths

Total Number of hadith in Sunan Ibn Majah (سنن ابن ماجه) are 4340 and the book is divided into 39 chapters.

Abū ʿAbd al-Raḥmān Aḥmad ibn Shuʿayb ibn ʿAlī ibn Sinān ibn Baḥr ibn Dīnar al-Khurasānī al-Nasāʾī, the collector of the hadith Book Sunan Nasai (سنن النسائي), was born in (829 AD) in Nasa, Khorasan and died in the city Ramla or Mecca in (915 AD). His dedication to his work led him to travel extensively, visiting key locations such as the Arabian Peninsula and seeking knowledge from scholars in Iraq, Kufa, the Hijaz, Syria, and Egypt. His collection of hadiths, Sunan Nasai, stands as a significant contribution to Islamic literature.

As per the hafiz Ibn Hajr Alaih, al-Nasa'i's teachers were too numerous to name. Still, they included Ishaq Ibn Rahwayh, Imam Abu Daud Al-Sijistani, Sunan Abu Dawood) and Qutayba ibn Sa'id. an-Nasa'i began to lecture In Egypt, mostly narrating ahadith to the extent that he became known by the title "Hafizul Hadeeth

The total hadith in Sunan Nasai (سنن النسائي) are 5760, The book is divided into 57 chapters, each focusing on a specific aspect of Islami c teachings and practices.

Muhammad ibn Isa Al-Tirmidhi, the collector of the hadith Book Jami Tirmizi (جامعة الترمذي), was born in (824 AD) in Termez, Uzbekistan and died in the same city he was born in (892 AD).

Imām Al-Tirmidhī was an Islamic scholar and collector of hadith from Termez (early Khorasan and present-day Uzbekistan). He wrote al-Jami` as-Sahih (Jami` at-Tirmidhi), one of Sunni Islam's six canonical hadith compilations. He also wrote Shama'il Muhammadiyah (popularly known as Shama'il at-Tirmidhi), a compilation of hadiths concerning the person and character of the Islamic prophet Muhammad. Al-Tirmidhi was also well-versed in Arabic grammar, favoring the school of Kufa over Basra due to the former's preservation of Arabic poetry as a primary source.

Al-Tirmidhi began studying hadith at the age of 20. From the year 235 AH (849/850), he traveled widely in Khurasan, Iraq, and the Hijaz to collect hadith.

The Total Number of hadith in Jami Tirmizi (جامعة الترمذي) is 3954, and the book is divided into 51 chapters.