He is the great imam, scholar, leader of the believers in hadeeth, Abu ‘AbdAllah Muhammad ibn Ismaa’eel ibn Ibraaheem al-Bukhaari, later known as Imam Bukhari, was born in Bukhara, eastern part of Turkestan on 13 Shawwal, 194 A.H. The newly-born child had scarcely opened his eyes in the world when he lost his eyesight. His father was immensely grieved at it. His pious mother wept and prayed to Allah to restore the eyesight of her newly-born child. And by the Grace of Allah, the eyesight of the newly-born child was fully restored. His father Ismail was a well-known and famous Muhaddith in his time and had been blessed with the chance of being in the company of Imam Malik, Hammad Ibn Zaid and also Abdullah Ibn Mubarak.
He began his study of the Hadith at the early age of eleven. In his 16th year, he made pilgrimage along with his mother and elder brother. There he attended the lectures of the great teachers of Hadith in Makkah and Madinah. He was still 18 years old, when he wrote a book on the decisions made by the Companions of the Prophet Muhammad (May Allah honour Him and grant Him Peace) and their followers.
He started on a study pilgrimage of the world of Islam, which lasted 16 years. Of this period, he spent five years in Basrah, visiting Egypt, Hijaz, Kufa and Baghdad several times and wandered all over Western Asia in quest of knowledge and learning. During his travels he reported ahadith from 80,000 persons. With the help of his exceptional memory he could retain these ahadith with all their sources in his mind to be penned down at an opportune time. He traveled a great deal in order to expand his knowledge.
Al-Bukhaari had more than one thousand shaykhs whom he met in the countries and cities to which he travelled. Among them were: Imam Ahmad ibn Hanbal, Hammaad ibn Shaakir, Makki ibn Ibraaheem and Abu ‘Aasim al-Nabeel (May Allah have Mercy on Them All).
Allaamah Nawawi (May Allah have Mercy on Him) relates that all scholars in Islam have agreed that Sahih Al Bukhari has earnestly gained the reward of being the most authentic after the Glorious Qur'an. He died, May Allah have mercy on him, on the night of Eid al-Fitr, 256 AH, at the age of 62. 
Imam Bukhari's memory was considered to be inhuman, for as soon as the praying of a hadith would finish Bukhari would repeat it orally. It has been known that in his childhood he had memorized many ahadiths.
Imām al-Bukhārī (rahimahullah) first started listening and learning ahādīth in 205 A.H., and after benefiting from the `ulama of his town he started his travels in 210 A.H. His memory was considered to be one of a kind; after listening to a hadīth he would repeat it from memory. It has been known that in his childhood he had memorized 2,000 ahādīth.
There is one spectacular incident which took place in Baghdad when Imam Bukhari took up temporary residence there. The people having heard of his many accomplishments, and the attributes which were issued to him, decided to test him so as to make him prove himself to them. In order to do that they chose one hundred different ahaadeeth and changing the testimonials and the text of the ahaadeeth they were then recited by ten people to Imam Bukhari.
There was a crowd of gathered people from within and outside the city to witness the outcome of such a test. When the ahaadeeth were recited Imam Bukhari replied to all in one manner, "Not to my knowledge." However, after the completion of all the ahaadeeth Imam Bukhari repeated each text and testimonial which had been changed followed by the correct text and testimonial, such was the memory of Imam Bukhari, as mentioned in Siyr Ala mun Nubala. (Biographies of noble people)
Ibn Khuzaymah (May Allah have mercy on him) said: I have never seen anyone beneath the canopy of heaven who has more knowledge of the ahadeeth of the Messenger of Allah (May Allah honour Him and grant Him Peace) and who has memorized more (hadeeth) than al-Bukhaari.
His monumental work, Sahih Al Bukhari established his reputation as one of the greatest compilers of Ahadith in Islam. It is said that Bukhari retained in his memory one million Ahadith of the Prophet Muhammad (May Allah honour Him and grant Him Peace) with all the details of their sources and reporters. Out of the million Ahadith which he had learnt from some 80,000 reporters, he selected 7,275 Ahadith including hadith occurring repeatedly. It has been said that this number excluding repeated ahadith is 4,000 and, according to Ibn Hajar (May Allah have mercy on him) it is 9,082 and without repetition this number reduces to around 2,602. This is from a total of around 600,000 traditions that the Imam Bukhari collected. He took 16 years to complete it.
Uncountable commentaries and ‘Sharuh’ (explanations) have been written for this ‘Sahih Al Bukhari’, the most prominent one is that of Hafiz ibn Hajar Assqalani, titled as ‘ Fath al Bari’.
Before he actually placed a hadith in his compilation he performed ghusl and prayed two raka`ah nafl prayers asking Allah for guidance. He finalized each hadith in the rawdah of Masjid an-Nabawi (between the Prophet's grave and his minbar) and wrote the hadīth in the masjid. Only after being completely satisfied with a hadīth did he give it a place in his collection. 
Al-Bukhari was a man with a very strong memory: It seemed as if his body, from head to toe, stored information. His superb memory reminds us of Abu Hurairah (may Allah be pleased with him). Sulaiman ibn Mujahid said, “One day, I was present in the company of Muhammad ibn Salam. He said, ‘If you had come earlier, I would have shown you the child who has 70,000 hadiths in his memory.’ Sulaiman stood up from his company and started looking for Al-Bukhari. Shortly he found him and asked, ‘Are you the one who has committed 70,000 hadiths to memory?’ Al-Bukhari replied, ‘I have learned more hadiths than this by heart. I even know the place of birth, death, and residence of most of those Companions from whom the hadiths are narrated.’”
Also, Muhammad ibn Azhar As-Sajistani said, “I used to go to Sulaiman ibn Harb accompanied by Imam Al-Bukhari to listen to hadiths. I used to write the hadiths, but Imam Al-Bukhari wouldn’t. Someone said to me, ‘Why doesn’t Imam Al-Bukhari note the hadiths down?’ I told him, ‘If you missed any Hadith in writing, you could obtain it from the memory of Imam Al-Bukhari.’” 
Imam Bukhari laid down the strictest conditions for acceptance of hadith for his Sahih:
Imam Bukhari wrote many books beside Sahih Al Bukhari (Al Jamius Sahih).Hereunder are some books written by Imam Bukhari.
In the year 864/250, he settled in Nishapur. It was there that he met Muslim ibn Al-Hajjaj, who would be considered his student, and eventually collector and organizer of the hadith collection Ṣaḥīḥ Muslim which is considered second only to that of al-Bukhārī.